Physics Progression Grid (9-12)
Theoretical Concepts Progression Grid
Note 1: It is assumed that students will already have knowledge (and be able to apply it as needed in their current class) of what they learnt in their previous grades, so SLOs from previous grades are not repeated in the higher grades. In practice teachers may want to refresh concepts with their students as appropriate.
Note 2:Teachers and schools are free to switch aruond SLOs among Grades 9 and 10 according to their teaching preferences. Similarly they are free to switch around SLOs among Grades 11 and 12 with each other.
Domain A: Physical Quantities and Measurement
Physics is the study of relationships between physical quantities. This involved quantitifying them by developing units of measurement, taking readings with instruments to make measurements and expressing how certain or uncertain one is about the soundness of the readings taken.
Standard: Students will be able to:
- express and mathematically maniupulate basic and derived physical quantities
- identify and explain the reasons for common sources of human and systematic error in experiments
- identify, explain and describe the ultility of measuring instruments in terms of precision
- quanitfy the uncertainty in readings taken and calculations made through those raw readings
Benchmark I: Understand that physical quantities can be classified into basic and derived quantities. Physical quantities can be measured, but emperical measurements are accompanied by sources of error.
Benchmark I: Understand that physical equations must be dimensionally consistent, and sources of error in measurements can be quantified. These errors can be compounded when measured quantities are used to calculate further derived quantities.
Differentiate between physical and non-physical quantities
Explain with examples that Science is based on physical quantities which consist of numerical magnitude and a unit.
Differentiate between base and derived physical quantities.
List the seven units of System International (SI) alongwith their symbols and physical quantities (standard definitions of SI units are not required).
Interconvert the prefixes and their symbols to indicate multiple and sub-multiple for both base and derived units.
Write the answer in scientific notation in measurements and calculations.
Recall that a scalar quantity has magnitude (size) only and that a vector quantity has magnitude and direction
Identify and explain how
that the following quantities are scalars: distance, speed, time, mass, energy and temperature
Identify and explain
that the following quantities are vectors: displacement, force, weight, velocity, acceleration, momentum, electric field strength and gravitational field strength
Determine, by calculation or graphically, the resultant of two vectors at right angles
Make reasonable estimates of quantities included in this curriculum
Theory of Measurment:
Describe how to measure a variety of lengths with appropriate precision using tapes, rulers, micrometers and verneir callpiers (including reading the scale on analogue callipers and micrometers)
Describe how to use a measuring cylinder to measure the volume of a liquid and to determine the volume of a solid by displacement
Describe how to measure a variety of time intervals using clocks and digital timers
Determine an average value for a small distance and for a short interval of time by measuring multiples (including the period of oscillation of a pendulum)
Round off calculations based on emperical data to an appropriate number of significant figures
Identify sources of, and suggest corrections for, systematic and random error in experiments
Differentiate between the accuracy and precision of data collected by measuring instruments
Determine the least count of a data collection instrument from its scale
9. [SLO: P-09-A-20]
Design experiments that mitigate sources of error by having a large data set, and averaging over the readings
10. [SLO: P-09-A-21]
Explain how parallex error is caused, and recommend how to prevent it from occuring in experiments
Recall that all physical quantities consist of a numerical magnitude and a unit
Make reasonable estimates of physical quantities included within the syllabus
Recall the following SI base quantities and their units: mass (kg), length (m), time (s), current (A), temperature (K)
Express derived units as products or quotients of the SI base units and use the derived units for quantities listed in this syllabus as appropriate
use SI base units to check the homogeneity of physical equations
derive formulae in simple cases using dimensions.
recall and use the following prefixes and their symbols to indicate decimal submultiples or multiples of both base and derived units: pico (p), nano (n), micro (μ), milli (m), centi (c), deci (d), kilo (k), mega (M), giga (G), tera (T)
Uncertainties in Measurement:
Explain the effects of systematic errors (including zero errors) and random errors in measurements
between precision and accuracy
assess the uncertainty in a derived quantity by simple addition of absolute, fractional or percentage uncertainties
explain why all measurements contain some uncertainty.
Domain B: Kinematics
Kinematics is the study of the motion of mechanical points, bodies and systems without consideration of their associated physical properties and the forces acting on them.
Standard: Students will be able to:
- differentiate between and mathematically manipulate scalar and vector quantities
- descibe and analytically and graphically analyse distance, displacement, speed, velocity, and acceleration
Benchmark I: Describe and analyze translatory motion in one dimension through analytical and graphical manipulation of scalar and vector quantities
Benchmark I: Describe and analyze translatory and rotational motion in a plane through analytical and graphical manipulation of scalar and vector quantities
Identify different types of motion i.e; translatory, (linear, random, and circular); rotatory and vibratory motions and distinguish among them.
Differentiate with examples between distance and displacement, speed and velocity.
Define speed as distance travelled per unit time and define velocity as change in displacement per unit time
Recall and use the equation speed = distance/time v = s/t
Recall and use the equation average speed = total distance travelled/total time taken
Define acceleration as change in velocity per unit time; recall and use the equation acceleration = change in velocity/time taken a = ∆v/∆t
Derive the units of acceleration as m/s2 from the formula a = ∆v/∆t
State what is meant by, and describe examples of, uniform acceleration and non-uniform acceleration
Recall that a deceleration is a negative acceleration and use this in calculations
Sketch, plot and interpret distance–time and speed–time graphs
Determine from the shape of a distance–time graph when an object is:
(a) at rest
(b) moving with constant speed
Determine from the shape of a speed–time graph when an object is:
(a) at rest
(b) moving with constant speed
(c) moving with constant acceleration
(d) moving with changing acceleration
State that the acceleration of free fall g for an object near to the surface of the Earth is approximately constant and is approximately 9.8m/s2
Calculate speed from the gradient of a distance–time graph
Derive how the gradient of the distance vs time graph gives the speed (without calculus)
Calculate the area under a speed–time graph to determine the distance travelled for motion with constant speed or constant acceleration
Deriving how the area beneath a speed vs time graph gives the distance travelled (without calculus)
Calculate acceleration from the gradient of a speed–time graph
Derive how the gradient of the speed vs time graph gives the acceleration (without calculus)
Explain that according to relativity, there is a universal speed limit for any object in the universe that is set to approximately 3x10^8 m/s
between scalar and vector quantities and give examples of scalar and vector quantities included in the syllabus
Add and subtract coplanar vectors
represent a vector as two perpendicular components
derive, from the definitions of velocity and acceleration, equations that represent uniformly accelerated motion in a straight line
solve problems using equations that represent uniformly accelerated motion in a straight line, including the motion of bodies falling in a uniform gravitational field without air resistance
define the radian and express angular displacement in radians
define angular displacement, angular velocity and angular acceleration and express angular displacement in radians.
solve problems by using S= r θ and v=rω . recall and use ω = 2π/T
state and use of equations of angular motion to solve problems involving rotational motions.
describe qualitatively motion in a curved path due to a perpendicular force.
derive and use centripetal acceleration a = rω², a = v² /r.
Domain C: Forces
Standard: Students will be able to:
- Differentiate between different kinds of forces and their effects
- Use Newton's laws to analyze motion and equilibrium
Benchmark I: Describe and analyse the effects of forces and momentum on the translational and rotational motion of bodies in one dimension
Benchmark I: Explain events in terms of Newton’s laws, including the Law of Gravitation, and the law of conservation of momentum in up to two dimensions
Mass, Weight and Gravity:
State that mass is a measure of the quantity of matter in an object at rest relative to the observer
State that the mass of an object resists change from its state of rest or motion (inertia)
Define a force as a push or pull
Define weight as the force exerted on an object with mass by a planet's gravity
State that a gravitational field is a region in which a mass experiences a force due to gravitational attraction
Define gravitational field strength as force per unit mass; recall and use the equation gravitational field strength = weight/mass g = W/m and know that this is equivalent to the acceleration of free fall
Describe how to determine mass using an electronic balance
Describe how to measure weight using a force meter
Describe the use of parabolic flights to simulate 'zero gravity' for astronauts preparing for journeys into space.
Types of Forces and Newton's Laws
Identify and use different types of force, including weight (gravitational force), friction, drag, air resistance, tension (elastic force), electrostatic force, magnetic force, thrust (driving force) and contact force
State that there are four fundamental forces and describe them in terms of their relative strengths:
- The strong force holds the nucleus of an atom together. it has a relative strength of 1, and acts within a range of 10^-15 m
- The electromagnetic force is a source of attraction and repulsion between charges and between sources of magnetism. It has a relative strength of 1/137, and does not have a limited range of influence
- The weak force is the cause of radioactive decay of atoms. It has a relative strength of !0^-6, and acts within a range of 10^-18 m
- The gravitational force is the cause of attraction between objects with mass. It has a relative strength of 10^-39, and does not have a limited range of influence
Identify forces acting on an object and draw free-body diagram(s) representing the forces
State Newton’s first law as ‘an object either remains at rest or continues to move in a straight line at constant speed unless acted on by a resultant force’
State that a force may change the velocity of an object by changing its direction of motion or its speed
Determine the resultant of two or more forces acting along the same straight line
State Netwon's second law of motion in terms of acceleration as 'The acceleration on an object is directly proportional to the result force applied to it and inversely proportional to its mass'
Recall and use the equation resultant force = mass × acceleration F = ma
State and apply Newton’s third law as ‘when object A exerts a force on object B, then object B exerts an equal and opposite force on object A’
Know that Newton’s third law describes pairs of forces of the same type acting on different objects
Recognize that Newton’s Laws are not exact but provide a good approximation, unless an object is moving close to the speed of light or is small enough that quantum effects become significant
- In the case of high speed bodies, the theory of relativistic mechanics is used
- In the case of very small objects at the subatomic level, quantum mechanics is used.
Identify when an object is in the below types of equilibrium:
Describe and give examples of how friction as a force may impede motion and produce heating (e.g. rubbing hands together produces heat, asteroids that enter the Earth's atmosphere disintegrate due to high temperature generated from air resistance)
Understand the motion of objects acted on by a constant weight or driving force, with and without drag (including air resistance or resistance in a liquid)
Explain how an object reaches terminal velocity
Define the thinking distance, braking distance and stopping distance of a moving vehicle
Explain the factors that affect thinking and braking distance including speed, tiredness, alcohol, drugs, load, tyre surface and road conditions
Explain, with examples, how rolling friction is much lesser than sliding friction (no need for coefficients of friction)
list various methods to reduce friction.
Define momentum as mass × velocity; recall and use the equation p = mv
Define impulse as force × time for which force acts; recall and use the equation impulse = FΔt = Δ(mv)
Apply the principle of the conservation of momentum to solve simple problems in one dimension
Define resultant force as the change in momentum per unit time; recall and use the equation resultant force = change in momentum/time taken F = ∆p/∆t
use a vector triangle to represent coplanar forces in equilibrium
explain that projectile motion is two dimensional motion in a vertical plane.
communicate the ideas of a projectile in the absence of air resistance that the
(i) Horizontal component (VH) of velocity is constant.
(ii) Acceleration is in the vertical direction and is the same as that of a vertically free falling object.
(iii) The horizontal motion and vertical motion are independent of each other.
evaluate using equations of uniformly accelerated motion that for a given initial velocity of frictionless projectile.
- How higher does it go?
- How far would it go along the level land?
- Where would it be after a given time?
- How long will it remain in air?
determine for a projectile launched from ground height the
- launch angle that results in the maximum range.
- relation between the launch angles that result in the same range.
describe how air resistance affects both the horizontal component and vertical component of velocity and hence the range of the projectile.
apply the principle of conservation of momentum to solve simple problems, including elastic and inelastic interactions between objects in both one and two dimensions (knowledge of the concept of coefficient of restitution is not required), such as:
- karate chops to break a pile of bricks
- car crashes
- ball & bat
- the motion under thrust of a rocket in a straight line considering short thrusts during which the mass remains constant
recall that, for an elastic collision, total kinetic energy is conserved and the relative speed of approach is equal to the relative speed of separation
understand that, while momentum of a system is always conserved in interactions between objects, some change in kinetic energy may take place
that a gravitational field is an example of a field of force and define gravitational field as force per unit mass
represent a gravitational field by means of field lines
that, for a point outside a uniform sphere, the mass of the sphere may be considered to be a point mass at its centre
recall and use Newton’s law of gravitation F = Gm1m2 /r2 for the force between two point masses
analyse circular orbits in gravitational fields by relating the gravitational force to the centripetal acceleration it causes
that a satellite in a geostationary orbit remains at the same point above the Earth’s surface, with an orbital period of 24 hours, orbiting from west to east, directly above the Equator
derive, from Newton’s law of gravitation and the definition of gravitational field, the equation g = GM/r2 for the gravitational field strength due to a point mass
recall and use g = GM/r2
why g is approximately constant for small changes in height near the Earth’s surface
define gravitational potential at a point as the work done per unit mass in bringing a small test mass from infinity to the point
use ϕ = –GM/r for the gravitational potential in the field due to a point mass
Explain how the concept of gravitational potential leads to the gravitational potential energy of two point masses and use EP = –GMm/r
Standard: Students will be able to analyze circular and rotational motion in terms of forces and momentum
Benchmark I: Describe and analyse the dynamics of rotational motion quantitatively and circular motion qualitatively in terms of forces in one dimension
Benchmark I: Describe and analyse the dynamics of rotational and circular motion in terms of forces and momentum in one dimension
Define like and unlike parallel forces.
Describe the moment of a force as a measure of its turning effect and give everyday examples
Define the moment of a force as moment = force × perpendicular distance from the pivot; recall and use this equation
State and use the principle of moments for an object in equilibrium
Describe an experiment to verify the principle of moments
State what is meant by centre of gravity
Describe how to determine the position of the centre of gravity of a plane lamina using a plumb line
Describe, qualitatively, the effect of the position of the centre of gravity on the stability of simple objects
Explain that the stability of an object can be improved by lowering the centre of mass and increasing the base area of the object and that this concept is central to engineering technology such as balancing toys and racing cars
Explain that an analagous to Newton's 1st law for translational motion, an object that is rotating will continue to do so at the same rate unless acted upon by a resultant moment (in which case it would begin to accelerate or decelerate its rotational motion)
Describe, qualitatively, motion in a circular path due to a force perpendicular to the motion as:
(a) speed increases if force increases, with mass and radius constant
(b) radius decreases if force increases, with mass and speed constant
(c) an increased mass requires an increased force to keep speed and radius constant ( F = mv2/r is not required)
Describe how artificial satellites orbit the Earth due to gravity providing centripetal force
Circular Motion & Centripetal Force:
solve problems using centripetal force F = mrω², F = mv² /r.
describe situations in which the centripetal acceleration is caused by a tension force, a frictional force, a gravitational force, or a normal force.
explain when a vehicle travels round a banked curve at the specified speed for the banking angle, the horizontal component of the normal force on the vehicle causes the centripetal acceleration.
describe the equation tanθ = v2/rg, relating banking angle θ to the speed v of the vehicle and the radius of curvature r.
explain that satellites can be put into orbits round the earth because of the gravitational force between the earth and the satellite.
explain that the objects in orbiting satellites appear to be weightless.
describe how artificial gravity is created to counter balance weightless.
analyze that satellites can be used to send information between places on the earth which are far apart, to monitor conditions on earth , including the weather, and to observe the universe without the atmosphere getting in the way.
describe that communication satellites are usually put into orbit high above the equator and that they orbit the earth once a day so that they appear stationary when viewed from earth.
define moment of inertia of a body and angular momentum.
derive a relation between torque, moment of inertia and angular acceleration.
explain conservation of angular momentum as a universal law and describe examples of conservation of angular momentum.
use the formulae of moment of inertia of various bodies for solving problems.
identify the direction of rocket thrusts necessary to cause a space vehicle to change direction along a circular arc in a region of space where gravity is negligible
explain how a centrifuge is used to separate materials using centripetal force
explain how angular momentum is used:
- by flywheels to store rotational energy
- by gyroscopes in navigation systems
- by ice skaters to adjust their angular velocity
Standard: Students will be able to analyze the effects of forces on the deformation of solids
Benchmark II: Describe and analyse in one dimension, analytically and graphically, how forces can cause solids to stretch and compress
Benchmark II: Describe and analyse the deformation of solids, analytically and graphically, in terms of how forces and pressure can cause stretching, compression, stress and strain
Deformation of Solids:
that forces may produce a change in size and shape of an object
Define the spring constant as force per unit extension; recall and use the equation spring constant = force/extension k = F/x
Sketch, plot and interpret load–extension graphs for an elastic solid and describe the associated experimental procedures
Define and use the term ‘limit of proportionality’ for a load–extension graph and identify this point on the graph (an understanding of the elastic limit is not required)
Recognise that small-scale vibrations can be modelled using Hooke's law, and these models have applications in many disciplines such as seismology, molecular mechanics and acoustics.
Explain that Hooke's law is the fundamental principle behind engineering many measurement instruments such as the spring scale, the galvanometer, and the balance wheel of the mechanical clock.
Deformation of Solids:
distinguish between the structure of crystalline, glassy, amorphous and polymeric solids.
describe that deformation in solids is caused by a force and that in one dimension, the deformation can be tensile or compressive.
that deformation is caused by tensile or compressive forces (forces and deformations will be assumed to be in one dimension only)
use the terms load, extension, compression and limit of proportionality
recall and use Hooke’s law
recall and use the formula for the spring constant k = F/ x
define and use the terms stress, strain and the Young modulus
describe an experiment to determine the Young modulus of a metal in the form of a wire understand and use the terms elastic deformation, plastic deformation and elastic limit
that the area under the force–extension graph represents the work done
determine the elastic potential energy of a material deformed within its limit of proportionality from the area under the force–extension graph
recall and use EP = 21 Fx = 21 kx2 for a material deformed within its limit of proportionality
Domain D: Energy, Work and Power
This field deails with what is the physical nature of energy and how can it be converted and harnessed for the benefit of society.
Standard: Students will be able to:
- differentiate between work, energy and power
- use the law of conservation of energy to analyze the viability and efficiency of systems
- differentiate between and mathemtically analyse kinetic and gravitational potential energy
Benchmark I: Describe and analyzie the effects of energy transfers and energy transformations on a body, along with the advantages and disadvantages of harnessing energy from natural resources
Benchmark I: Describe and analyse analytically and graphically the effects of energy transfers and energy transformations on a body
Define work and its SI unit.
Recall and use the equation work done = force × distance moved in the direction of the force W = Fd
Define energy as the ability to do work
State that energy may be stored as kinetic, gravitational potential, chemical, elastic (strain), nuclear, electrostatic and internal (thermal)
Prove that Kinetic Energy Ek = ½ mv2 (use of equations of motion not needed; proof through kinematic graphs will suffice) and potential energy Ep = mgh and solve problems using these equations.
Describe how energy is transferred between stores during events and processes, including examples of transfer by forces (mechanical work done), electrical currents (electrical work done), heating, and by electromagnetic, sound and other waves
Know the principle of the conservation of energy and apply this principle to the transfer of energy between stores during events and processes
Apply the principle of conservation of energy to explain why ideas to create perpetual energy machines do not work
Recall and use the equation for kinetic energy Ek= 1/2mv2
Recall and use the equation for the change in gravitational potential energy ΔEp = mgΔh
List renewable and non-renewable energy sources
Describe how useful energy may be obtained, or electrical power generated, from:
(a) chemical energy stored in fossil fuels
(b) chemical energy stored in biofuels
(c) hydroelectric resources
(d) solar radiation
(e) nuclear fuel
(f) geothermal resources
(i) waves in the sea
including references to a boiler, turbine and generator where they are used
Describe advantages and disadvantages of each method limited to whether it is renewable, when and whether it is available, and its impact on the environment
Define efficiency as:
(a) (%) efficiency = (useful energy output)/(total energy input) ( × 100%)
(b) (%) efficiency = (useful power output)/(total power input) ( × 100%)
and recall and use these equations
explain why a system cannot have an efficiency of 100%.
Define power as work done per unit time and also as energy transferred per unit time; recall and use the equations
(a) power = work done/time taken P = W/t
(b) power = energy transferred/time taken P = ∆E/t
derive, using the equations of motion, the formula for kinetic energy EK = 1/2mv2
describe that work can be calculated from the area under the force-displacement graph.
differentiate conservative and non conservative forces giving examples of each.
utilize work – energy theorem in a resistive medium to solve problems.
Domain E: Heat and Thermodynamics
Standard: Students should be able to describe and analyze:
- the effects of heat on the physical properties of matter by making reference to the kinetic theory of matter
- how heat can be transferred through different modes
Benchmark I: Use the kinetic theory of matter to explain the physical properties of matter and how these transform upon changes in state
Benchmark I: Use the kinetic theory of matter to account for the properties of an ideal gas
Define density as mass per unit volume; recall and use the equation density = mass/volume ρ = m/V
Describe how to determine the density of a liquid, of a regularly shaped solid and of an irregularly shaped solid which sinks in a liquid (volume by displacement), including appropriate calculations
Particle Theory of Matter:
the distinguishing properties of solids, liquids and gases
Describe, qualitatively, the particle structure of solids, liquids and gases, relating their properties to the forces and distances between particles and to the motion of the particles (atoms, molecules, ions and electrons)
Describe plasma as a fourth state of matter in which a significant portion of the material is made up of ions or electrons e.g. in stars, neon lights and lightning streamers
Recognise that under extreme physical conditions, atoms can break down into sub-atomic particles that can form unusual states of matter such as degenerate matter (usually made of any one kind of subatomic particle such as neutron degenerate matter in neutron stars under strong gravity and heat) and Bose-Einstein condensates (created when certain materials are taken to very low temperatures and then exhibit remarkable properities like superconductivity and superfluidity)
Define temperature (as quantity which determine the direction of flow of thermal energy).
Define heat (as the energy transferred resulting from the temperature difference between two objects).
Describe the relationship between the motion of particles and temperature, including the idea that there is a lowest possible temperature (−273°C), known as absolute zero, where the particles have least kinetic energy
Convert temperatures between kelvin and degrees Celsius; recall and use the equation T (in K) = θ (in °C) + 273
Recall that an increase in the temperature of an object increases its internal energy
Describe an increase in temperature of an object in terms of an increase in the average kinetic energies of all of the particles in the object
Explain that lasers (through absorption and re-emission of focused light with the right wavelength spectrum and amplitude) can be used to increase or decrease the vibrational kinetic energy of atoms in order to raise and lower the temperature of materials to extremes (working of a laser, concept of photons and coherence is not required). This allows for experimements on Earth to study the properties of matter in extreme conditions such as may be the case in space like in stars.
Explain how a physical property which varies with temperature may be used for the measurement of temperature and state examples of such properties.
Explain the need for fixed points and state what is meant by the ice point and steam point.
Discuss sensitivity, range and linearity of thermometers.
Describe the structure and action of liquid-in-glass thermometers (including clinical) and of a thermocouple thermometer, showing an appreciation of its use for measuring high temperatures and those which vary rapidly.
Describe and explain how the structure of a liquid-in-glass thermometer affects its sensitivity, range and linearity
Define specific heat capacity as the energy required per unit mass per unit temperature increase; recall and use the equation specific heat capacity = change in energy mass × change in temperature c = ∆E m∆θ
Describe experiments to measure the specific heat capacity of a solid and of a liquid
Give examples of everyday effects due to the large specific heat of water.
Thermal Expansion and Kinetic Theory of Matter:
Recall and use the terms for the changes in state between solids, liquids and gases (including deposition and sublimation)
Explain that the bimetallic strip used in thermostat is based on different rate of expansion of different metals on heating.
Explain applications and consequences of thermal expansion in the context of common examples, including the liquid-in-glass thermometer
Explain, in terms of the motion and arrangement of particles, the thermal expansion of solids, liquids and gases, and state the relative order of magnitudes of the expansion of solids, liquids and gases state the meaning of melting point and boiling point
Describe melting, solidification, boiling and condensation in terms of energy transfer without a change in temperature
Recall the melting and boiling temperatures for water at standard atmospheric pressure
Describe qualitatively the thermal expansion of solids (linear and volumetric expansion).
Explain the thermal expansion of liquids (real and apparent expansion).
Gases, Pressure and Thermal Expansion:
Describe the pressure and the changes in pressure of a gas in terms of the forces exerted by particles colliding with surfaces, creating a force per unit area
Explain qualitatively, in terms of particles, the relationship between:
(a) pressure and temperature at constant volume
(b) volume and temperature at constant pressure
(c) pressure and volume at constant temperature
Recall and use the equation p1V1 = p2V2, including a graphical representation of the relationship between pressure and volume for a gas at constant temperature
Changes in State:
Describe melting, solidification, boiling and condensation in terms of energy transfer without a change in temperature
Describe the differences between boiling and evaporation
Describe evaporation in terms of the escape of more energetic particles from the surface of a liquid
Describe how temperature, humidity, surface area and air movement over a surface affect evaporation
Explain how evaporation causes cooling
Describe the use of cooling caused by evaporation in refrigeration process without using harmful CFC.
Describe latent heat as the energy required to change the state of a substance and explain it in terms of particle behaviour and the forces between particles
Describe experiments to determine heat of fusion and heat of vaporization of ice and water respectively by sketching temperature-time graph on heating ice.
Explain that certain materials, when cooled to near absolute zero, can exhibit:
- superconductivity. In this state the vibrational kinetic energy of the atoms are minimal, and so there is minimum resistance (theoretically none) to the flow of electrons.
- superfluidity. In this state a liquid will experience zero friction between the molecules of the liquid (zero viscosity). This allows for superfluids to creep over the walls of containers to 'empty' themselves. It also implies that if you stir a superfluid, the vortices will keep spinning indefinitely.
define and use specific heat capacity
define and use specific latent heat and distinguish between specific latent heat of fusion and specific latent heat of vaporisation
Recall that (thermal) energy is transferred from a region of higher temperature to a region of lower temperature
that regions of equal temperature are in thermal equilibrium
Recall that a physical property that varies with temperature may be used for the measurement of temperature and state examples of such properties, including the density of a liquid, volume of a gas at constant pressure, resistance of a metal, e.m.f. of a thermocouple
Recall that the scale of thermodynamic temperature does not depend on the property of any particular substance
Recall that internal energy is determined by the state of the system and that it can be expressed as the sum of a random distribution of kinetic and potential energies associated with the molecules of a system
relate a rise in temperature of an object to an increase in its internal energy
convert temperatures between kelvin and degrees Celsius and recall that T/K = θ/ °C + 273.15
Recall that the lowest possible temperature is zero kelvin on the thermodynamic temperature scale and that this is known as absolute zero
Recall that amount of substance is an SI base quantity with the base unit mol
use molar quantities where one mole of any substance is the amount containing a number of particles of that substance equal to the Avogadro constant NA
Recall that a gas obeying pV ∝
T, where T is the thermodynamic temperature, is known as an ideal gas
recall and use the equation of state for an ideal gas expressed as pV = nRT, where n = amount of substance (number of moles) and as pV = NkT, where N = number of molecules
recall that the Boltzmann constant k is given by k = R/NA
state the basic assumptions of the kinetic theory of gases
recall and use W = p∆V for the work done when the volume of a gas changes at constant pressure and understand the difference between the work done by the gas and the work done on the gas
recall and use the first law of thermodynamics ∆U = q + W expressed in terms of the increase in internal energy, the heating of the system (energy transferred to the system by heating) and the work done on the system
explain how molecular
movement causes the pressure exerted by a gas and derive and use the
relationship pV = 3Nm
Recall that the root-mean-square speed cr.m.s. is given by < > c2
compare pV = 3Nm
recognise that the model of ideal gases is used a base from which the field of statistical mechanics emerged, and has helped explain the behavior of 'non-ideal' gases through modifications to the model e.g. the behavior of stars
Benchmark II: Explain how heat can be transferred through convection, conduction and radiation and the effects and applications of these modes of transfer
Modes of Heat Transfer:
Describe experiments to distinguish between good and bad thermal conductors
Describe thermal conduction in all solids in terms of atomic or molecular lattice vibrations and also in terms of the movement of free (delocalised) electrons in metallic conductors
Explain convection in liquids and gases in terms of density changes and describe experiments to illustrate convection
Explain convection in seawater to support marine life
Describe the role of land breezes and sea breezes in maintaining moderate costal climates
Explain how birds are able to fly for hours without flapping their wings and gliders are able to rise by riding on thermal currents which are streams of hot air rising in the sky.
Describe the process of thermal energy transfer by infrared radiation and know that it does not require a medium
Describe the effect of surface colour (black or white) and texture (dull or shiny) on the emission, absorption and reflection of infrared radiation
Describe how the rate of emission of radiation depends on the surface temperature and surface area of an object
Describe experiments to distinguish between good and bad emitters of infrared radiation
Describe experiments to distinguish between good and bad absorbers of infrared radiation
Explain the consequence of heat radiation in greenhouse effect and its effect in global warming.
Explain everyday applications using ideas about conduction, convection and radiation, including:
(a) heating objects such as kitchen pans
(b) heating a room by convection
(c) measuring temperature using an infrared thermometer
(d) using thermal insulation to maintain the temperature of a liquid and to reduce thermal energy transfer
(e) the mechanism of a household hot-water system
Domain F: Fluid Statics & Dynamics
Standard: Students shouuld be able to :
- Differentiate between and analyze the effects of pressure on solids, liquids and gases
- Analyze how pressure can vary in and be transfered across a static liquid
- Analyze how pressure and energy affects the dynamics of flowing liquids
Benchmark I: Understand and analyse the nature and effects of pressure on and in static solids and fluids
Benchmark I: Understand and analyse the nature and effects of pressure and energy on the dynamics of incompressible fluids
Define pressure as force per unit area; recall and use the equation pressure = force/area p = F/A
Describe how pressure varies with force and area in the context of everyday examples
State that the pressure at a surface produces a force in a direction at right angles to the surface and describe an experiment to show this
explain that the atmosphere exerts a pressure.
describe how the height of a liquid column may be used to measure the atmospheric pressure.
describe that atmospheric pressure decreases with the increase in height above the Earth’s surface.
explain that changes in atmospheric pressure in a region may indicate a change in the weather.
Describe how the height of a liquid column in a liquid barometer may be used to determine the atmospheric pressure
Describe, quantitatively, how the pressure beneath the surface of a liquid changes with depth and density of the liquid
Recall and use the equation for the change in pressure beneath the surface of a liquid change in pressure = density × gravitational field strength × change in height ∆p = ρg∆h
Describe the use of a manometer in the measurement of pressure difference.
State and apply Pascal's law to systems such as the transmission of pressure in hydraulic systems with particular reference to the hydraulic press and hydraulic brakes on vehicles.
Explain how the design of the wings of an aeroplane make use of difference in air pressure to create a lift force while in flight
Explain how the partial pressures of gases in the atmosphere affect the proportion of dissolved gases in water bodies and in biological lifeforms that inhale air like human beings
Explain how decompression sickness can be caused when subadivers rise to quickly from deep underwater due to the reduction of ambient pressure that causes dissolved gases in the blood to form bubbles
derive, from the definitions of pressure and density, the equation for hydrostatic pressure ∆p = ρg∆h
use the equation ∆p = ρg∆h
understand that the upthrust acting on an object in a fluid is due to a difference in hydrostatic pressure
calculate the upthrust acting on an object in a fluid using the equation F = ρgV (Archimedes’ principle)
explain how ships are engineered to float in the sea in terms of principle of flotation
define the terms: steady (streamline or laminar) flow, incompressible flow and non viscous flow as applied to the motion of an ideal fluid.
explain that at a sufficiently high velocity, the flow of viscous fluid undergoes a transition from laminar to turbulence conditions.
describe that the majority of practical examples of fluid flow and resistance to motion in fluids involve turbulent rather than laminar conditions.
describe equation of continuity Aν = Constant, for the flow of an ideal and incompressible fluid and solve problems using it.
explain that for water falling from a tap, when the flow rate increases the cross sectional area decreases as mandated by the continuity equation.
identify that the equation of continuity is a form of the principle of conservation of mass.
describe that the pressure difference can arise from different rates of flow of a fluid (Bernoulli effect).
describe that the pressure difference can arise from different rates of flow of a fluid (Bernoulli effect).
derive Bernoullie equation in the form P + ½ ρv2 + ρgh = constant for the case of horizontal tube of flow.
interpret and apply Bernoulli Effect in the: filter pump, Venturi meter, in, atomizers, flow of air over an aerofoil and in blood physics.
describe that real fluids are viscous fluids.
describe that viscous forces in a fluid cause a retarding force on an object moving through it.
analyse how the below applications work because of the Bernoulli efftect:
- atomisers in perfume bottles and paint sprayers
- the swinging trajectory of a spinning cricket ball and the lift of a spinning gold ball (the magnus effect)
- the use of Ventur ducts in filter pumps and car enginers to ajust the flow of fluid
Domain G: Waves
In this field students study the physical nature of waves and how the propagate, with a special look at the cases of sound and light
Standard: Students should be able to mathetically describe how waves propagate and the general properties of reflection, refraction and diffraction
Benchmark I: Explain wave motion in terms of oscillations and energy and apply the basic principles of wave reflection, refraction and diffraction to solve problems
Benchmark I: Analytically and graphically explain the nature and effects of simple harmonic motion, the doppler effect, and attentuation of sound wave intensity in media
Recall that waves transfer energy without transferring matter
Describe what is meant by wave motion as illustrated by vibrations in ropes and springs and by experiments using water waves
Describe the features of a wave in terms of wavefront, wavelength, frequency, crest (peak), trough, amplitude and wave speed
Define the terms:
(a) frequency as the number of wavelengths that pass a point per unit time
(b) wavelength as the distance between two consecutive, identical points such as two consecutive crests
(c) amplitude as the maximum distance from the mean position
5. Derive, recall and use the equation wave speed = frequency × wavelength v = f λ
that for a transverse wave, the direction of vibration is at right angles to the direction of the energy transfer, and give examples such as electromagnetic radiation, waves on the surface of water, and seismic S-waves (secondary)
Explain that for a longitudinal wave, the direction of vibration is parallel to the direction of the energy transfer, and give examples such as sound waves and seismic P-waves (primary)
Explain how tsunamis are generated in terms of underwater earthquakes/volcanic activity generating waves that increase in frequency and amplitude as they encounter increasingly shallow water
Describe how waves can undergo:
(a) reflection at a plane surface
(b) refraction due to a change of speed
(c) diffraction through a gap
Describe how wavelength and gap size affects diffraction through a gap
Describe the use of a ripple tank to show:
(a) reflection at a plane surface
(b) refraction due to a change in speed caused by a change in depth
(c) diffraction due to a gap
(d) diffraction due to an edge
Describe how wavelength affects diffraction at an edge
Describe the production of sound by vibrating sources
Describe the longitudinal nature of sound waves and describe compressions and rarefactions
State the approximate range of frequencies audible to humans as 20Hz to 20000Hz
Explain why sound waves cannot travel in a vacuum and describe an experiment to demonstrate this
Describe how changes in amplitude and frequency affect the loudness and pitch of sound waves
Describe how different sound sources produce sound waves with different qualities (timbres), as shown by the shape of the traces on an oscilloscope
Describe an echo as the reflection of sound waves
Describe simple experiments to show the reflection of sound waves
Describe a method involving a measurement of distance and time for determining the speed of sound in air
[SLO: P-10-G-25] Recall that the speed of sound in air is approximately 330–350m/s
Recall that, in general, sound travels faster in solids than in liquids and faster in liquids than in gases
Define ultrasound as sound with a frequency higher than 20kHz
Describe the uses of ultrasound in cleaning, prenatal and other medical scanning, and in sonar (including calculation of depth or distance from time and wave speed)
Describe the use of infrasound by elephants in communication, and in the study of seismic activity
Explain the effects of noise pollution on the environment
Describe the importance of acoustic protection
Describe how knowledge of the properties of sound waves is applied in the design of buildings with respect to acoustics
Explain the use of soft materials to reduce echo sounding in classroom studies, and other public gathering buildings.
Explain, with examples, how sound can reflect, refract and diffract
Explain that sound is converted by the ear drum and nerves into electrical signals that are then interpreted by the brain
describe what is meant by wave motion as illustrated by vibration in ropes, springs and ripple tanks
and use the terms displacement, amplitude, phase difference, period, frequency, wavelength and speed
the use of the time-base and y-gain of a cathode-ray oscilloscope (CRO) to determine frequency and amplitude
derive, using the definitions of speed, frequency and wavelength, the wave equation v = f λ
recall and use v = f λ
understand that energy is transferred by a progressive wave
recall and use intensity = power/area and intensity ∝
(amplitude)2 for a progressive wave
compare transverse and longitudinal waves
analyse and interpret graphical representations of transverse and longitudinal waves
Explain that when a source of sound waves moves relative to a stationary observer, the observed frequency is different from the source frequency (understanding of the Doppler effect for a stationary source and a moving observer is not required)
use the expression fο = f sv /(v ± vs) for the observed frequency when a source of sound waves moves relative to a stationary observer
• explain the applications of Doppler effect such as radar, sonar, astronomy, satellite, radar speed traps and studying cardiac problems in humans (mathematical account of relativistic doppler effect is not required)
Simple Harmonic Motion:
describe simple examples of free oscillations.
and use the terms displacement, amplitude, period, frequency, angular frequency and phase difference in the context of oscillations, and express the period in terms of both frequency and angular frequency
Explain that simple harmonic motion occurs when acceleration is proportional to displacement from a fixed point and in the opposite direction
use a = –ω2x and recall and use, as a solution to this equation, x = x0 sin ωt
use the equations v = v0 cos ωt and v = ±ω ( ) x x 02 2 −
analyse and interpret graphical representations of the variations of displacement, velocity and acceleration for simple harmonic motion
describe the interchange between kinetic and potential energy during simple harmonic motion
recall and use E = 1/2mω2x02 for the total energy of a system undergoing simple harmonic motion
understand that a resistive force acting on an oscillating system causes damping
and use the terms light, critical and heavy damping and sketch displacement–time graphs illustrating these types of damping
hat resonance involves a maximum amplitude of oscillations and that this occurs when an oscillating system is forced to oscillate at its natural frequency
describe practical examples of free and forced oscillations (resonance).
describe practical examples of damped oscillations with particular reference to the efforts of the degree of damping and the importance of critical damping in cases such as a car suspension system.
describe qualitatively the factors which determine the frequency response and sharpness of the resonance.
identify the use of standing waves and resonance in applications such as rubens tubes, chladni plates and acoustic levitation (knowiledge of wave harmonic modes is not required)
explain the importance of critical damping in a car suspension system
identify that there are some circumstances in which resonance is useful such as tuning a radio, microwave oven and other circumstances in which resonance should be avoided such as aeroplane’s wing or a suspension bridge
Standard: Students should be able to explain how the wave theory of light can help explain various optical phenomena
Benchmark I: Use the principles of reflection and refraction from the wave model of light to create and analyse ray diagrams that help explain images generated by simple mirrors, lenses and total internal reflection
Benchmark I: Use wave theory to analyse diffraction patterns, interference and polarization in the context of light and sound and other waves
Define and use the terms normal, angle of incidence and angle of reflection
State that light travels in straight lines (assuming it is in the same medium and not under the influence of extreme gravity), and describe an experiment to prove this
Describe an experiment to illustrate the law of reflection
Describe an experiment to find the position and characteristics of an optical image formed by a plane mirror (same size, same distance from mirror as object and virtual)
State that for reflection, the angle of incidence is equal to the angle of reflection and use this in constructions, measurements and calculations
Define and use the terms normal, angle of incidence and angle of refraction
Apply the qualitative principle that a wave bends towards the normal when it slows down while entering a medium, and that it bends away from the normal if it speeds up when it enters a new medium (in the case the angle of incidence is zero, then the waves continues parallel to the normal)
Define the refractive index from a vaccum to a medium for light as c/v
Define refractive index n as n = sin i/sin r; recall and use this equation
Describe an experiment to show refraction of light by transparent blocks of different shapes
Define the terms critical angle and total internal reflection; derive, recall and use the equation n = 1/sin c
Describe experiments to show internal reflection and total internal reflection
Describe the use of optical fibres, particularly in telecommunications, stating the advantages of their use in each context
Describe the action of thin converging and thin diverging lenses on a parallel beam of light
Define and use the terms focal length, principal axis and principal focus (focal point)
Draw ray diagrams to illustrate the formation of real and virtual images of an object by a converging lens and know that a real image is formed by converging rays and a virtual image is formed by diverging rays
Define linear magnification as the ratio of image length to object length; recall and use the equation linear magnification = image length/object length
Describe the use of a single lens as a magnifying glass
Describe the dispersion of light (including the detection of non-visible spectra by a thermometer) as illustrated by the refraction of white light by a glass prism
the traditional seven colours of the visible spectrum in order of frequency and in order of wavelength
Describe the use of a single lens as a magnifying glass and in a camera, projector and photographic enlarger and draw ray diagrams to show how each forms an image.
Explain that extreme gravity from interstellar objects like blackholes can cause light to apparently bend (from the perspective of the observer) in a way that is analagous to a simple lens. This is called 'gravitational lensing'.
Explain that with the help of 3D printers, it is possible to develop 'acoustic lenses' that are made of materials and shapes that work to focus or diverge sound
state that all electromagnetic waves are transverse waves that travel with the same speed c in free space
recall the approximate range of wavelengths in free space of the principal regions of the electromagnetic spectrum from radio waves to γ-rays
recall that wavelengths in the range 400–700nm in free space are visible to the human eye
Explain that polarisation is a phenomenon associated with transverse waves
recall and use Malus’s law (I = I0 cos2θ ) to calculate the intensity of a plane-polarised electromagnetic wave after transmission through a polarising filter or a series of polarising filters (calculation of the effect of a polarising filter on the intensity of an unpolarised wave is not required)
explain and use the principle of superposition
experiments that demonstrate stationary waves using microwaves, stretched strings and air columns (it will be assumed that end corrections are negligible; knowledge of the concept of end corrections is not required)
explain the formation of a stationary wave using a graphical method, and identify nodes and antinodes
Recall how wavelength may be determined from the positions of nodes or antinodes of a stationary wave
explain the meaning of the term diffraction
experiments that demonstrate diffraction including the qualitative effect of the gap width relative to the wavelength of the wave; for example diffraction of water waves in a ripple tank
Recall, use and explain the terms interference and coherence
explain beats as the pulsation caused by two waves of similar frequences interfering with each other
• recognise that beats are generated in musical instruments
• explain the use of polaroids in sky photography and stress analysis of materials
• explain that gravitational waves are waves of the intensity of gravity generated by the accelerated masses of an orbital binary system that propagate as waves outward from their source at the speed of light
• recognise that as a gravitational wave passes a body with mass the distortion in spacetime can cause the body to stretch and compress periodically
• recognise that gravitational waves pass through the Earth due to far off celestial events, but they are very minute amplitude
• explain that interferometers are very sensitive detection devices that make use of the interference of laser beams (working and set up details are not required) and were used to first detect the existence of gravitational waves
Diffraction and Interference:
Recall, interpret and explain
experiments that demonstrate two-source interference using water waves in a ripple tank, sound, light and microwaves
understand the conditions required if two-source interference fringes are to be observed
recall and use λ = ax /D for double-slit interference using light
recall and use d sin θ = nλ
describe the use of a diffraction grating to determine the wavelength of light (the structure and use of the spectrometer are not included)
Electricity and Magnetism
This is the field that studies the physical properties of electric and magenetic phenomena, along with the nature of electromagnetism
Standard: Students should be able to describe mathematically the nature of static magnetic and electric fields
Benchmark I: Explain qualitatively the origin, properties, phenomena and applications of static magnetic and electric fields in terms of magnetic domain theory and elecrtic charges
Benchmark I: Analyse quantitatively the interactions of electric fields in terms of electric force, field strength, potential and potential energy
Describe the forces between magnetic poles and between magnets and magnetic materials, including the use of the terms north pole (N pole), south pole (S pole), attraction and repulsion, magnetised and unmagnetised
Describe induced magnetism
State the difference between magnetic and non-magnetic materials
State the differences between the properties of temporary magnets (made of soft iron) and the properties of permanent magnets (made of steel)
Describe a magnetic field as a region in which a magnetic pole experiences a force
Describe the plotting of magnetic field lines with a compass or iron filings and the use of a compass to determine the direction of the magnetic field
Draw the pattern and direction of the magnetic field lines around a bar magnet
State that the direction of the magnetic field at a point is the direction of the force on the N pole of a magnet at that point
that the relative strength of a magnetic field is represented by the spacing of the magnetic field lines
Describe uses of permanent magnets and electromagnets
Explain qualitatively in terms of the domain theory of magnetism how materials can be magnetised and demagnetised (stroking method, heating, orienting in north-south direction and striking, use of a solenoid)
Explain qualitativly terms of the domain theory of magnetism the differences between ferromagnetic, paramagnetic and diamagnetic materials in their reaction to external magnetic fields
Explain that the Earth has a magnetic field that:
- is opposite to its geographical north-south orientation
- protects life on the planet from cosmic radiation
- allows animals that make use of biomagnetism (e.g. many birds and turtles) to navigate during migration
Ilustrate applications of magets in recording technology, and how electronic devices need to be kept safe from strong magnetic fields
Explain that soft magnetic materials (such as soft iron) can be to provide shielding from magnetic fields
Explain how ferrofluids make use of temporary soft magnetic materials suspended in liquids to develop fluids that react to the poles of a magnet and have many applications in fields such as electronics
State that there are positive and negative charges and that charge is measured in coulombs
State that unlike charges attract and like charges repel
Describe experiments to show electrostatic charging by friction
Explain that charging of solids by friction involves only a transfer of negative charge (electrons)
Explain how and why an insulator can be discharged by:
- putting it above a flame
- exposing it to damp conditions
Explain how a conductor can be charged by electric induction and then "earthing"
Describe examples where charging could be a problem, e.g. lightning.
Describe examples where charging is helpful, e.g. photocopier and electrostatic precipitator.
Describe an electric field as a region in which an electric charge experiences a force
State that the direction of an electric field line at a point is the direction of the force on a positive charge at that point
Describe simple electric field patterns, including the direction of the field:
(a) around a point charge
(b) around a charged conducting sphere
(c) between two oppositely charged parallel conducting plates (end effects will not be examined)
State examples of electrical conductors and insulators
Describe an experiment to distinguish between electrical conductors and insulators
Recall and use a simple electron model to explain the difference between electrical conductors and insulators
Explain how a lightning rod can protect humans from electrocution from lightning strikes
Explain that electrical breakdown occurs when a strong electric field passes through a material and causes its atoms to ionize. Corona discharge and Lichtenburg figures are visible examples of electrical breakdown.
Explain how lightning is generated:
- through friction between the water molecules suspended in clouds in the case of thunderstorms, and from between smoke particules in the case of volcanic lightning
- lightning streamers are created through the process of electrical breakdown and this provided a path for the electric current from one charged object to the other
- in the case of cloud-ground lightning a strong electric field from the clouds induces an opposite net charge in the conducting material present in the ground, and when this field becomes strong enough it generates lightning streams that provide the path for cloud-to-ground and ground-to-cloud discharge
Explain that there are many kinds of atmospheric lightning (e.g. sprites, jets, elves, trolls, pixies, ghosts, ball lightning) that are still being researched
Explain the workings and applications of a Van De Graaf generator
Explain how a Faraday cage works by inducing internal electric fields that work to shield the inside from the influence of external electric fields
Recall that an electric field is an example of a field of force and define electric field as force per unit positive charge
recall and use F = qE for the force on a charge in an electric field
represent an electric field by means of field lines
recall and use E = ∆V/∆d to calculate the field strength of the uniform field between charged parallel plates
describe the effect of a uniform electric field on the motion of charged particles
Recall that, for a point outside a spherical conductor, the charge on the sphere may be considered to be a point charge at its centre
recall and use Coulomb’s law F = Q1Q2 /(4πε0r2) for the force between two point charges in free space
recall and use E = Q/(4πε0r2) for the electric field strength due to a point charge in free space
define electric potential at a point as the work done per unit positive charge in bringing a small test charge from infinity to the point
recall and use the fact that the electric field at a point is equal to the negative of potential gradient at that point
use V = Q/(4πε0r) for the electric potential in the field due to a point charge
Recall how the concept of electric potential leads to the electric potential energy of two point charges and use EP = Qq/(4πε0r)
define capacitance, as applied to both isolated spherical conductors and to parallel plate capacitors
recall and use C = Q/V
derive, using C = Q/V, formulae for the combined capacitance of capacitors in series and in parallel
use the capacitance formulae for capacitors in series and in parallel
determine the electric potential energy stored in a capacitor from the area under the potential–charge graph
recall and use W = 21 QV = 21 CV2
analyse graphs of the variation with time of potential difference, charge and current for a capacitor discharging through a resistor
recall and use τ = RC for the time constant for a capacitor discharging through a resistor
use equations of the form x = x0 e–(t/RC) where x could represent current, charge or potential difference for a capacitor discharging through a resistor
list the use of capacitors in various household appliances such as in flash gun of camera, refrigerator, electric fan, rectification circuit etc.
Standard: Students should be able to analyze and account for the distribution of current, voltage and resistance in simple DC circuits
Benchmark I: Apply knowledge of the relationships between electric current, voltage, resistance and power in simple circuits to understand their applications (in technology and in nature) and the need for safety measures in electric appliances
Benchmark I: Derive and use Kirchhoff's laws to understand the design and application of simple circuits
Electric Current and Ohm's Law:
Define electric current as the charge passing a point per unit time; recall and use the equation electric current = charge/time I = Q/t
Describe electrical conduction in metals in terms of the movement of free electrons
Recall that current is measured in amps (amperes) and that the amp is given by coulomb per second (C/s)
Know the difference between direct current (d.c.) and alternating current (a.c.)
State that conventional current is from positive to negative and that the flow of free electrons is from negative to positive
Describe the use of ammeters (analogue and digital) with different ranges
Define e.m.f. (electromotive force) as the electrical work done by a source in moving a unit charge around a complete circuit; recall and use the equation e.m.f. = work done (by a source) charge E = W/Q
Define p.d. (potential difference) as the work done by a unit charge passing through a component; recall and use the equation p.d. = work done (on a component) charge V = W/Q
Know that e.m.f. and p.d. are measured in volts and that the volt is given by joule per coulomb (J/C)
Describe the use of voltmeters (analogue and digital) with different ranges
Calculate the total e.m.f. where several sources are arranged in series
State that the e.m.f of identical sources connected in parallel is equal to the e.m.f. of one of the sources
Recall and use the equation resistance = p.d./current R = V/I
Describe an experiment to determine resistance using a voltmeter and an ammeter and do the appropriate calculations
Recall and use, for a wire, the direct proportionality between resistance and length, and the inverse proportionality between resistance and cross-sectional area
State Ohm’s law, including reference to constant temperature
Sketch and explain the current–voltage graphs for a resistor of constant resistance, a filament lamp and a diode
Describe the effect of temperature increase on the resistance of a resistor, such as the filament in a filament lamp
Draw and interpret circuit diagrams with cells, batteries, power supplies, generators, oscilloscopes, potential dividers, switches, resistors (fixed and variable), heaters, thermistors (NTC only), light-dependent resistors (LDRs), lamps, motors, ammeters, voltmeters, magnetising coils, transformers, fuses, relays, diodes and light-emitting diodes (LEDs), and know how these components behave in the circuit
Recall and use in calculations, the fact that:
(a) the current at every point in a series circuit is the same
(b) the sum of the currents entering a junction in a parallel circuit is equal to the sum of the currents that
leave the junction
(c) the total p.d. across the components in a series circuit is equal to the sum of the individual p.d.s across
(d) the p.d. across an arrangement of parallel resistances is the same as the p.d. across one branch in the
arrangement of the parallel resistances
Calculate the combined resistance of two or more resistors in series
Calculate the combined resistance of two resistors in parallel
Calculate current, voltage and resistance in parts of a circuit or in the whole circuit
Describe the action of negative temperature coefficient (NTC) thermistors and light-dependent resistors and explain their use as input sensors
Describe the action of a variable potential divider
Recall and use the equation for two resistors used as a potential divider R1/R2= V1/V2
Explain how the values of resistors are chosen according to a colour code and why widely different values are needed in different types of circuit.
Discuss the need to choose components with suitable power ratings.
Describe the action of a diode in passing current in one direction only.
Describe the action of a light-emitting diode in passing current in one direction only and emitting light.
Describe and explain the action of relays in switching circuits.
Describe and explain circuits operating as light-sensitive switches and temperature-operated alarms (using a relay or other circuits).
State common uses of electricity, including heating, lighting, battery charging and powering motors and electronic systems
State the advantages of connecting lamps in parallel in a lighting circuit
Recall and use the equation power = current × voltage P = IV
Recall and use the equation energy = current × voltage × time E = IVt
Define the kilowatt-hour (kWh) and calculate the cost of using electrical appliances where the energy unit is the kWh
State the hazards of:
(a) damaged insulation
(b) overheating cables
(c) damp conditions
(d) excess current from overloading of plugs, extension leads, single and multiple sockets when using a mains supply
Explain the use and operation of trip switches and fuses and choose appropriate fuse ratings and trip switch settings
Explain what happens when a live wire touches a metal case that is earthed
Explain why the outer casing of an electrical appliance must be either non-conducting (double-insulated) or earthed
Recall that a mains circuit consists of a live wire (line wire), a neutral wire and an earth wire and explain why a switch must be connected into the live wire for the circuit to be switched off safely
Explain why fuses and circuit breakers are connected into the live wire
38. Explain why domestic supplies are connected in parallel.
Explain the damage that can electric shock could do to a human being in terms of burns, cardio-respiratory failure and seizures
Explain that in humans and many other living organisms:
- cells control the flow of specific charged elements across the membrane with proteins that sit on the cell surface and create an opening for certain ions to pass through. These proteins are called ion channels.
- When a cell is stimulated, it allows positive charges to enter the cell through open ion channels. The inside of the cell then becomes more positively charged, which triggers further electrical currents that can turn into electrical pulses, called action potentials.
- The bodies of many organisms use certain patterns of action potentials to initiate the correct movements, thoughts and behaviors.
State that there several species of aquatic life, such as Electrophorus Electricus, that can naturally generate external electric shocks through internal biological mechanisms that act as batteries
Explain, with examples of animals with this ability, that electroreception is the ability to detect weak naturally occurring electrostatic fields in the environment.
Computer Science Physics:
Explain that electronic devices are built from circuits that:
- can act as switches that can convert incoming voltage into binary electrical pulses of high and low (or 1 and 0). This is called Boolean logic and is the basis for converting analogue data to digital data. A 'bit' is the smallest unit of data in computing; either 1 or 0. Eight bits make up a byte.
- these switches can be put into combinations that then allow them to achieve complex logical operations
- transistors are very economical and rapid-response circuit components that function as switches
- with advances in engineering, the number of transistors that can be fit per unit area onto a circuit board has continued to increase dramatically; this has rapidly enhanced computing power
- circuits that maintain their 'state' after receiving an input can be said to exhibit 'memory' since they retain the effect of the last action upon them
- circuit systems that allow for logical processing and memory functions form the basis of progammable electronics
- modern day electronic systems are now making use of 'artificial intelligence'; computer systems that can 'learn' the right/best response to a situation by processing vasts amounts of data
- technologies like AI and computer simulation softwares are allowing physicists to tackle problems that require finding patterns in vast amounts of data e.g. climate predictions, astronomy and seismology
- breakthroughs in quantum physics are causing a new revolution in computing that are enabling computers to make exponentially more logical operations per unit time than with traditional computers
- quantum computers use 'qubits' rather than traditional bits. Rather than relying on transistors to store bits, they rely on materials like liquids at very low temperatures (that then exhibit 'quantum' properties) that under the right conditions can also store memory and 'digitise' incoming analogue data. However a qubit does not only store 1 or 0. It can store many more possibilities at the same time (analagous to having coordinates in 3 dimensions rather than just along the x axis). This is the basis for why quantum computing is much more powerful than traditional computing.
- quantum computers are still in early stages of development, and have to overcome manufacturing challenges such core components only functing at very cold temperatures that are at almost absolute zero
Differentiate between analogue and digital electronics.
Compare an analogue wrist watch with a digital wrist watch with reference to energy conversions and time display on dials.
Describe the action of a bipolar npn transistor as an electrically operated switch and explain its use in switching circuits.
State in words and in truth table form, the action of the following logic gates, AND, OR, NAND, NOR and NOT (inverter).
Identify the use of logic gates for security purposes (e.g; burglar alarm, fire extinguisher etc.).
State the symbols for the logic gates listed above (American ANSI Y 32.14 symbols will be used).
Describe the use of a bistable circuit.
Discuss the fact that bistable circuits exhibit the property of memory.
Recall hat an electric current is a flow of charge carriers
understand that the charge on charge carriers is quantised
recall and use Q = It
use, for a current-carrying conductor, the expression I = Anvq, where n is the number density of charge
define the potential difference across a component as the energy transferred per unit charge
recall and use V = W/Q
recall and use P = VI, P = I2R and P = V2 /R
recall and use V = IR
sketch the I–V characteristics of a metallic conductor at constant temperature, a semiconductor diode and a filament lamp
explain that the resistance of a filament lamp increases as current increases because its temperature
state Ohm’s law
recall and use R = ρL/A
Recall that the resistance of a light-dependent resistor (LDR) decreases as the light intensity
Recall that the resistance of a thermistor decreases as the temperature increases (it will be
assumed that thermistors have a negative temperature coefficient)
recall and use the circuit symbols shown in section 6 of this syllabus
draw and interpret circuit diagrams containing the circuit symbols shown in section 6 of this syllabus
define and use the electromotive force (e.m.f.) of a source as energy transferred per unit charge in
driving charge around a complete circuit
distinguish between e.m.f. and potential difference (p.d.) in terms of energy considerations
Explain the effects of the internal resistance of a source of e.m.f. on the terminal potential difference
recall Kirchhoff’s first law and understand that it is a consequence of conservation of charge
recall Kirchhoff’s second law and understand that it is a consequence of conservation of energy
derive, using Kirchhoff’s laws, a formula for the combined resistance of two or more resistors in series
use the formula for the combined resistance of two or more resistors in series
derive, using Kirchhoff’s laws, a formula for the combined resistance of two or more resistors in parallel
use the formula for the combined resistance of two or more resistors in parallel
use Kirchhoff’s laws to solve simple circuit problems
Explain the principle of a potential divider circuit
recall and use the principle of the potentiometer as a means of comparing potential differences
Explain the use of a galvanometer in null methods
explain the use of thermistors and light-dependent resistors in potential dividers to provide a potential difference that is dependent on temperature and light intensity
explain the internal resistance of sources and its consequences for external circuits
Explain how inspectors can easily check the reliability of a concrete bridge with carbon fibres as the fibres conduct electricity
Standard: Students should be able to:
- explain how power can be generated through electromagnetic induction
- account for how motors make use of electromagnetism to generate kinetic energy
- analyse AC circuits in terms of current, resistance, reactance, voltage, and impedance
Benchmark I: Apply qualitatively the principles of electromagnetic forces, induction and radiation to understand:
(1) how electricity can be generated
(2) how elecitricity can be harnessed in systems that make use of motors
(3) the physical properties of electromagnetic radition and their applications
Benchmark I: Apply quantitatively the principles of magnetic flux, electromagnetic forces, induction and radiation to understand:
(1) how electricity can be generated
(2) how alternating current in circuits can be regulated
(3) the applications of electromagnetic radition in medical technology
Describe an experiment to demonstrate electromagnetic induction
State that the magnitude of an induced e.m.f. is affected by:
(a) the rate of change of the magnetic field or the rate of cutting of magnetic field lines
(b) the number of turns in a coil
State and use the fact that the effect of the current produced by an induced e.m.f. is to oppose the change producing it (Lenz’s law) and describe how this law may be demonstrated
Describe a simple form of a.c. generator (rotating coil or rotating magnet) and the use of slip rings and brushes where needed
Sketch and interpret graphs of e.m.f. against time for simple a.c. generators and relate the position of the generator coil to the peaks, troughs and zeros of the e.m.f.
Describe the pattern and direction of the magnetic field due to currents in straight wires and in solenoids and state the effect on the magnetic field of changing the magnitude and direction of the current
Describe how the magnetic effect of a current is used in relays and loudspeakers and give examples of their application
8. Describe an experiment to show that a force acts on a current-carrying conductor in a magnetic field, including the effect of reversing:
(a) the current
(b) the direction of the field
Recall and use the relative directions of force, magnetic field and current
Describe the magnetic field patterns between currents in parallel conductors and relate these to the forces on the conductors (excluding the Earth’s field)
Recall that a current-carrying coil in a magnetic field may experience a turning effect and that the turning effect is increased by increasing:
(a) the number of turns on the coil
(b) the current
(c) the strength of the magnetic field
Explain that it is theorized that the Earth's magnetic field is generated by the rotation of the Earth and its molten iron core that contains charged particles in motion
Describe the operation of an electric motor, including the action of a split-ring commutator and brushes
Describe the structure and explain the principle of operation of a simple iron-cored transformer
Use the terms primary, secondary, step-up and step-down
Recall and use the equation VpVs= NpNs where P and S refer to primary and secondary
State the advantages of high-voltage transmission and explain why power losses in cables are smaller when the voltage is greater
State that electrons are emitted by a hot metal filament through a process called thermionic emission.
Explain that to cause a continuous flow of emitted electrons requires (1) high positive potential and (2) very low gas pressure.
Describe the deflection of an electron beam by electric fields and magnetic fields.
Describe the use of an oscilloscope to display waveforms
Describe how to measure p.d. and short intervals of time with an oscilloscope using the Y-gain and timebase
Recall the main regions of the electromagnetic spectrum in order of frequency and in order of wavelength
Recall that the speed of all electromagnetic waves in:
(a) a vacuum is 3.0 × 10^8 m/s
(b) air is approximately the same as in a vacuum
Describe the role of the following components in the stated applications:
(a) radio waves – radio and television communications, astronomy
(b) microwaves – satellite television, mobile (cell) phone, Bluetooth, microwave ovens
(c) infrared – household electrical appliances, remote controllers, intruder alarms, thermal imaging, optical
(d) visible light – photography, vision
(e) ultraviolet – security marking, detecting counterfeit bank notes, sterilising water
(f) X-rays – hospital use in medical imaging, security scanners, killing cancerous cells, engineering
applications such as detecting cracks in metal
(g) gamma rays – medical treatment in detecting and killing cancerous cells, sterilising food and medical
equipment, engineering applications such as detecting cracks in metal
Describe the damage caused by electromagnetic radiation, including:
(a) excessive exposure causing heating of soft tissues and burns
(b) ionising effects caused by ultraviolet (skin cancer and cataracts), X-rays and gamma rays (cell mutation
Explain qualitatively in terms of wavelength changes how scattering of light by molecules in the air give the sky its blue color during the day and its shades of red during sunset (use of the terms Rayleigh and Mei scattering are not required)
Explain that technology launched into space like the Hubble and James Webb telescopes are playing strong roles in interstellar research, and they rely on the diffraction and refraction of non-visible spectra to study objects that are not in direct line of 'sight'
Explain that theoretically light can also considered to be made of massless particles that carry energy and momentum called 'photons'. As an example of this particle nature, light exerts pressure on objects (very slight) and this has been used by satellites that have 'solar sails' that accelerate with the help of force from light rays.
Explain that a magnetic field is an example of a field of force produced either by moving charges or by permanent magnets
represent a magnetic field by field lines
Recall that a force might act on a current-carrying conductor placed in a magnetic field
recall and use the equation F = BIL sin θ, with directions as interpreted by Fleming’s left-hand rule
define magnetic flux density as the force acting per unit current per unit length on a wire placed at rightangles to the magnetic field
determine the direction of the force on a charge moving in a magnetic field
recall and use F = BQv sin θ
Recall the origin of the Hall voltage and derive and use the expression VH = BI /(ntq), where t = thickness
Explain the use of a Hall probe to measure magnetic flux density
describe the motion of a charged particle moving in a uniform magnetic field perpendicular to the direction of motion of the particle
explain how electric and magnetic fields can be used in velocity selection
sketch magnetic field patterns due to the currents in a long straight wire, a flat circular coil and a long solenoid
Recall that the magnetic field due to the current in a solenoid is increased by a ferrous core
explain the origin of the forces between current-carrying conductors and determine the direction of the forces
define magnetic flux as the product of the magnetic flux density and the cross-sectional area perpendicular to the direction of the magnetic flux density
recall and use Φ = BA
Recall and use the concept of magnetic flux linkage
Recall and explain experiments that demonstrate:
a- that a changing magnetic flux can induce an e.m.f. in a circuit
b- that the induced e.m.f. is in such a direction as to oppose the change producing it
c- the factors affecting the magnitude of the induced e.m.f.
recall and use Faraday’s and Lenz’s laws of electromagnetic induction
explain how seismometers make use of electromagnetic induction to the earthquake detection in terms of how:
(i) any movement or vibration of the rock on which the seismometer rests (buried in
a protective case) results in relative motion between the magnet and the coil
(suspended by a spring from the frame.
(ii) the emf induced in the coil is directly proportional to the displacement associated
Recall and use the terms period, frequency and peak value as applied to an alternating current or voltage
use equations of the form x = x0 sin ωt representing a sinusoidally alternating current or voltage
recall and use the fact that the mean power in a resistive load is half the maximum power for a sinusoidal alternating current
distinguish between root-mean-square (r.m.s.) and peak values and recall and use I r.m.s. = I0 / 2 and Vr.m.s. = V0 / 2 for a sinusoidal alternating current
distinguish graphically between half-wave and full-wave rectification
explain the use of a single diode for the half-wave rectification of an alternating current
explain the use of four diodes (bridge rectifier) for the full-wave rectification of an alternating current
analyse the effect of a single capacitor in smoothing, including the effect of the values of capacitance and the load resistance
define mutual inductance (M) and self-inductance (L), and their unit henry.
describe the phase of A.C and how phase lags and leads in A.C Circuits.
identify inductors as important components of A.C circuits termed as chokes (devices which present a high resistance to alternating current).
Calculate the reactances of capacitors and inductors.
describe impedance as vector summation of resistances and reactances.
Domain I: Modern Physics
This domain focuses on new fields of Physics that were developed in the 19th and 20th centuries. These include nuclear physics, relativity and quantum physics.
Standard: Students will be able to:
- Describe the standard model of particle physics
- Analyse radioactive decay procsses
- Explain the processes of nuclear fusion and fission
- Explain the postulates and implications of special relativity
- Use the quantum mechanical model of photons to explain phenomena
Benchmark XIV: Describe and explain, with reference to broad qualitative ideas from relativity, quantum mechanics and particle physics:
(1) the structure of atoms and atomic nuclei
(2) the origin of radioactivity and its uses and hazards.
Benchmark XIV: Explain and apply knowledge of the basic inter-related postulates of and discoveries from:
(1) the special theory of relativity
(2) the standard model of particle physics
(3) quantum theory
Describe the structure of the atom in terms of a positively charged nucleus and negatively charged electrons that go around the nucleus:
- These electrons do not go around in predictable circular paths in the way that planets go around the sun. The electrons behave as 'quantum particles' and their location and momentum at any point in time is governed by probability; one cannot predict the motion of an electron.
- The 'shells' in which electrons 'orbit' refer to the level of kinetic energy the electrons possess; the further the shell is from the nucleus, the more energy the electron has.
- If one were to 'look' at an atom, one would see a fuzzy 'cloud' of electrons with a very small nucleus in the center (akin to a football with flies around it in a boundary of several football fields).
Describe how alpha-particle scattering experiments provide evidence for:
(a) a very small nucleus surrounded by mostly empty space
(b) a nucleus containing most of the mass of the atom
(c) a nucleus that is positively charged
Describe the composition of the nucleus in terms of protons and neutrons
Describe how atoms form positive ions by losing electrons or negative ions by gaining electrons
Define the terms proton number (atomic number) Z and nucleon number (mass number) A and be able to calculate the number of neutrons in a nucleus
Explain the term nuclide and use the nuclide notation AZX
Explain what is meant by an isotope and state that an element may have more than one isotope
Describe the detection of alpha particles (α-particles) using a cloud chamber or spark counter and the detection of beta particles (β-particles) (β-particles will be taken to refer to β−) and gamma radiation (γ-radiation) by using a Geiger-Müller tube and counter
Use count rate measured in counts/s or counts/minute
Explain what is meant by background radiation
Recall the sources that make a significant contribution to background radiation including:
(a) radon gas (in the air)
(b) rocks and buildings
(c) food and drink
(d) cosmic rays
Use measurements of background radiation to determine a corrected count rate
Describe the emission of radiation from a nucleus as spontaneous and random in direction
Describe α-particles as two protons and two neutrons (helium nuclei), β-particles as high-speed electrons from the nucleus and γ-radiation as high-frequency electromagnetic waves
State, for α-particles, β-particles and γ-radiation:
(a) their relative ionising effects
(b) their relative penetrating powers
Describe the deflection of α-particles, β-particles and γ-radiation in electric fields and magnetic fields
Explain that radioactive decay is a change in an unstable nucleus that can result, most commonly (there other kinds of decay as well but students are not required to study those at this level), in the emission of α-particles or β-particles and/or γ-radiation and know that these changes are spontaneous and random.
Use decay equations, using nuclide notation, to show the emission of α-particles, β-particles and γ-radiation
Describe the process of fusion as the formation of a larger nucleus by combining two smaller nuclei with the release of energy, and recognise fusion as the energy source for stars
Recall that matter can be converted to energy and vice versa (in this way the law of conservation of energy still holds).
Describe the process of fission when a nucleus, such as uranium-235 (U-235), absorbs a neutron and produces daughter nuclei and two or more neutrons with the release of energy
Use E=mc^2 to calculate the energy released in the process of nuclear fusion and fission reactions
Explain how the neutrons produced in fission create a chain reaction and that this is controlled in a nuclear reactor, including the action of coolant, moderators and control rods
Define the half-life of a particular isotope as the time taken for half the nuclei of that isotope in any sample to decay; recall and use this definition in calculations, which may involve information in tables or decay curves
Describe the dating of objects by the use of 14C
Explain how the type of radiation emitted and the half-life of the isotope determine which isotope is used for applications including:
(a) household fire (smoke) alarms
(b) irradiating food to kill bacteria
(c) sterilisation of equipment using gamma rays
(d) measuring and controlling thicknesses of materials with the choice of radiations used linked to penetration and absorption
(e) diagnosis and treatment of cancer using gamma rays
State the effects of ionising nuclear radiations on living things, including cell death, mutations and cancer
Explain how radioactive materials are moved, used and stored in a safe way, with reference to:
(a) reducing exposure time
(b) increasing distance between source and living tissue
(c) use of shielding to absorb radiation
hat a quark is a fundamental particle and that there are six flavours (types) of quark: up, down, strange, charm, top and bottom
Recall and use the charge of each flavour of quark and understand that its respective antiquark has the opposite charge (no knowledge of any other properties of quarks is required)
Recall that protons and neutrons are not fundamental particles and describe protons and neutrons in terms of their quark composition
Recall that a hadron may be either a baryon (consisting of three quarks) or a meson (consisting of one quark and one antiquark)
Recall that electrons and neutrinos are fundamental particles called leptons
Explain that there are various contending theories about what 'mass' and 'force' are generated from e.g. that these are generated from quantum fields when they are energised, or from multidimensional 'strings' that vibrate in higher dimensions to give rise to particles (no further technical knowledge beyond these simple descriptions is expected at this level)
Explain that particle accelerators collide atoms and sub-atomic particles with each other at very high speeds by accelerating them using magnetic and electric fields across very long tunnels to generate new particles
Explain that antimatter is the counterpart of matter (e.g. a positron is the antimatter counterpart to an electron):
- Antiparticles usually have the same weight, but opposite charge, compared to their matter counterparts
- Most of the matter in the observable universe is matter
- The asymmetry of matter and antimatter in the universe is an unsolved mystery
- When a particle meets its corresponding antiparticle, they undergo annihilation reactions in which either all the mass is converted to heat and light energy, or some mass is left over the form of new subatomic particles
distinguish between inertial and non-inertial frames of reference.
describe the significance of Einstein’s assumption of the constancy of the speed of light.
identify that if c is constant then space and time become relative.
explain qualitatively and quantitatively the consequence of special relativity in relation to:
a– the relativity of simultaneity
b– the equivalence between mass and energy
c– length contraction
d– time dilation
e– mass increase
explain the implications of mass increase, time dilation and length contraction for space travel.
recognize that spacetime is a mathematical model in relativity that treats time as a fourth dimension of the traditional three dimensions of space. It can be thought of as a metaphorical sheet of paper that can bend, and when it bends it can cause effects such as stretching and compression seens when gravitational waves pass through objects.
infer from the results of the α-particle scattering experiment the existence and small size of the nucleus
describe a simple model for the nuclear atom to include protons, neutrons and orbital electrons
distinguish between nucleon number and proton number
Recall that isotopes are forms of the same element with different numbers of neutrons in their nuclei
Recall and use the notation AZ X for the representation of nuclides
Recall that nucleon number and charge are conserved in nuclear processes
describe the composition, mass and charge of α-, β- and γ-radiations (both β– (electrons) and β+ (positrons) are included)
Explain that an antiparticle has the same mass but opposite charge to the corresponding particle, and that a positron is the antiparticle of an electron
state that (electron) antineutrinos are produced during β–decay and (electron) neutrinos are produced during β+ decay
Explain that α-particles have discrete energies but that β-particles have a continuous range of energies because (anti)neutrinos are emitted in β-decay
represent α- and β-decay by a radioactive decay equation of the form U Th 92238902342 " + 4α12 use the unified atomic mass unit (u) as a unit of mass
Recall that a quark is a fundamental particle and that there are six flavours (types) of quark: up, down, strange, charm, top and bottom
recall and use the charge of each flavour of quark and understand that its respective antiquark has the opposite charge (no knowledge of any other properties of quarks is required)
recall that protons and neutrons are not fundamental particles and describe protons and neutrons in terms of their quark composition
Recall that a hadron may be either a baryon (consisting of three quarks) or a meson (consisting of one quark and one antiquark)
describe the changes to quark composition that take place during β– and β+ decay
recall that electrons and neutrinos are fundamental particles called leptons
Recall that electromagnetic radiation has a particulate nature
Explain that a photon is a quantum of electromagnetic energy
recall and use E = hf
use the electronvolt (eV) as a unit of energy
Explain that a photon has momentum and that the momentum is given by p = E/c (connect with the idea that light can exert a force)
understand that photoelectrons may be emitted from a metal surface when it is illuminated by electromagnetic radiation
understand and use the terms threshold frequency and threshold wavelength
explain photoelectric emission in terms of photon energy and work function energy
recall and use hf = Φ + 21mvmax2
explain why the maximum kinetic energy of photoelectrons is independent of intensity, whereas the photoelectric current is proportional to intensity
Explain that the photoelectric effect provides evidence for a particulate nature of electromagnetic radiation while phenomena such as interference and diffraction provide evidence for a wave nature
describe and interpret qualitatively the evidence provided by electron diffraction for the wave nature of particles
Explain the de Broglie wavelength as the wavelength associated with a moving particle
recall and use λ = h/p
Recallthat there are discrete electron energy levels in isolated atoms (e.g. atomic hydrogen)
Interpret and explain the appearance and formation of emission and absorption line spectra
recall and use hf = E1 – E2
• describe Compton effect qualitatively.
• explain the phenomena of pair production and pair annihilation.
• explain how the very short wavelength of electrons, and the ability to use electrons and magnetic fields to focus them, allows electron microscope to achieve very high resolution.
• use the uncertainty principle to explain why emperical measurements must necessarily have uncertainty in them
Recognize the equivalence between energy and mass as represented by E = mc2 and recall and use this equation
represent simple nuclear reactions by nuclear equations of the form 7N He O H 142481711 + + "
define and use the terms mass defect and binding energy
sketch the variation of binding energy per nucleon with nucleon number
explain what is meant by nuclear fusion and nuclear fission
explain the relevance of binding energy per nucleon to nuclear reactions, including nuclear fusion and nuclear fission
calculate the energy released in nuclear reactions using E = c2∆m
Explain that fluctuations in count rate provide evidence for the random nature of radioactive decay
Recall and explain that radioactive decay is both spontaneous and random
define activity and decay constant, and recall and use A = λN
use λ = 0.693/t21
Recall the exponential nature of radioactive decay, and sketch and use the relationship x = x0e–λt, where x could represent activity, number of undecayed nuclei or received count rate
describe the function of the principle components of a water moderated power reactor (core, fuel, rods, moderator, control rods, heat exchange, safety rods and shielding).
explain why uranium fuel needs to be enriched before use
compare the amount of energy released in a fission reaction with the (given) energy released in a chemical reaction.
Explain that a tracer is a substance containing radioactive nuclei that can be introduced into the body and is then absorbed by the tissue being studied
Explain that annihilation occurs when a particle interacts with its antiparticle and that mass–energy and momentum are conserved in the process
explain that, in PET scanning, positrons emitted by the decay of the tracer annihilate when they interact with electrons in the tissue, producing a pair of gamma-ray photons travelling in opposite directions
calculate the energy of the gamma-ray photons emitted during the annihilation of an electron-positron pair
Explain that the gamma-ray photons from an annihilation event travel outside the body and can be detected, and an image of the tracer concentration in the tissue can be created by processing the arrival times of the gamma-ray photons
Domain J: Astrophysics
This field studies the physical behavior of celestial objects
Students will be able to:
- describe the broad distribution of celestial bodies in the observable universe
- explain the evidence for the expansion of the universe
Benchmark I: Describe and explain, with broad reference to Newton's laws and special relativity, the structure and behavior of celestial objects in the observable universe
Benchmark I: Explain, with reference to findings from thermodynamics, quantum physics, and relativity:
(1) how the relative distances of celestial objects in the universe are mapped
(2) proof for the Big Bang theory
(a) the Earth is a planet that orbits the Sun once in approximately 365 days
(b) the orbit of the Earth around the Sun is an ellipse which is approximately circular
(c) the Earth rotates on its axis, which is tilted, once in approximately 24 hours
(d) it takes approximately one month for the Moon to orbit the Earth
(e) it takes approximately 500s for light from the Sun to reach the Earth
Define average orbital speed from the equation v = 2π r/T where r is the average radius of the orbit and T is the orbital period; recall and use this equation
Describe the Solar System as containing:
(a) one star, the Sun
(b) the eight named planets and know their order from the Sun
(c) minor planets that orbit the Sun, including dwarf planets such as Pluto and asteroids in the asteroid belt
(d) moons, that orbit the planets
(e) smaller Solar System bodies, including comets and natural satellites
Analyse and interpret planetary data about orbital distance, orbital period, density, surface temperature and uniform gravitational field strength at the planet’s surface
Recall that the strength of the gravitational field:
(a) at the surface of a planet depends on the mass of the planet
(b) around a planet decreases as the distance from the planet increases
Explain that the Sun contains most of the mass of the Solar System and that the strength of the gravitational field at the surface of the Sun is greater than the strength of the gravitational field at the surface of the planets
Explain that the force that keeps an object in orbit around the Sun is the gravitational attraction of the Sun
Explain that the strength of the Sun’s gravitational field decreases and that the orbital speeds of the planets decrease as the distance from the Sun increases
(a) galaxies are each made up of many billions of stars
(b) the Sun is a star in the galaxy known as the Milky Way
(c) other stars that make up the Milky Way are much further away from the Earth than the Sun is from the
(d) astronomical distances can be measured in light-years, where one light-year is the distance travelled in
a vacuum by light in one year
(e) the Sun and its solar system orbit the center of the Milky Way
Describe the life cycle of a star:
(a) a star is formed from interstellar clouds of gas and dust that contain hydrogen
(b) a protostar is an interstellar cloud collapsing and increasing in temperature as a result of its internal
(c) a protostar becomes a stable star when the inward force of gravitational attraction is balanced by an
outward force due to the high temperature in the centre of the star
(d) all stars eventually run out of hydrogen as fuel for the nuclear reaction
(e) most stars expand to form red giants and more massive stars expand to form red supergiants when
most of the hydrogen in the centre of the star has been converted to helium
(f) a red giant from a less massive star forms a planetary nebula with a white dwarf at its centre
(g) a red supergiant explodes as a supernova, forming a nebula containing hydrogen and new heavier
elements, leaving behind a neutron star or a black hole at its centre
(h) the nebula from a supernova may form new stars with orbiting planets
Recall that the Milky Way is one of many billions of galaxies making up the Universe and that the diameter
of the Milky Way is approximately 100000 light-years
Explain that the Sun is a star of medium size, consisting mostly of hydrogen and helium, and that it radiates most of its energy in the infrared, visible and ultraviolet regions of the electromagnetic spectrum
Explain that stars are powered by nuclear reactions that release energy and that in stable stars the nuclear reactions involve the fusion of hydrogen into helium
Describe redshift as an increase in the observed wavelength of electromagnetic radiation emitted from receding stars and galaxies
Explain that the light from distant galaxies shows redshift and that the further away the galaxy, the greater the observed redshift and the faster the galaxy’s speed away from the Earth
Describe, qualitatively, how redshift provides evidence for the Big Bang theory
Explain at regardless of whether you travel towards or away from a beam of light at any constant speed, you will always measure the speed of light as appox. 3x10^8 m/s. This is a counterintuitive fact and is a base assumption on which Einstein's theory of relativity is based.
State that objects travelling close to the speed of light will experience time dilation. Assume there are two twins, A and B, who begin at the same place on Earth and then suppose A stays on Earth and B goes on a rocket journey at nearly the speed of light. Then if B returns back to Earth after he/she measures to be one year, it could be that he/she discovers that for A and everyone on Earth 70-80 years have in fact passed.
Explain that gravitational fields can slow down time relative to objects far away i.e. if there were two twins on Planets A and B, where A was much more massive than B, then the twin on A would age much more slowly than the twin on B. If the twin on A felt that one year has gone by, it could be that the twin on B felt as if 50 years had actually gone by. This phenomenon is explained by Einstein's theory of relativity and is called Time Dilation.
Explain that it is hypothesized that most of the matter in the universe is made up of dark matter:
- It is 'dark' because it does not appear to interact with electromagnetic radiation
- The shaping and movement of many galaxies do not seem to be explanable without sources of gravity that cannot be observed with any technology developed so far; hence this source of gravity is called 'dark matter'
Use and explain the term luminosity as the total power of radiation emitted by a star
recall and use the inverse square law for radiant flux intensity F in terms of the luminosity L of the source F = L/(4πd2)
understand that an object of known luminosity is called a standard candle
he use of standard candles to determine distances to galaxies
recall and use Wien’s displacement law λmax ∝
1/T to estimate the peak surface temperature of a star
use the Stefan–Boltzmann law L = 4πσr2T4
use Wien’s displacement law and the Stefan–Boltzmann law to estimate the radius of a star
Explain that the lines in the emission and absorption spectra from distant objects show an increase in wavelength from their known values
use ∆λ / λ . ∆f/f . v /c for the redshift of electromagnetic radiation from a source moving relative to an observer
explain why redshift leads to the idea that the Universe is expanding
recall and use Hubble’s law v . H0d and explain how this leads to the Big Bang theory (candidates will only be required to use SI units)
Domain K: Climate Physics
Standard: Students should be able to explain, with reference to the physics of heat, how natural disasters are generated
Standard: Students should be able to explain, with context to the components of the Earth's systems, that the Earth's climate depends on energy flow and conversions on the surface of the planet as well as in exchange with outerspace
Use ideas of convection to explain how cyclones are formed
Explain how global warming can contribute to higher chances of extreme weather events in the case of:
- heat waves
- winter storms,
Use ideas of conduction, convection and radiation to explain how magma flows beneath the Earth, why it causes tectonic plate movement, volcanic eruptions and how the center of the Earth remains hot since being formed over 4 billion years ago
Describe Earth's climate system as a complex system having five interacting components: the atmosphere (air), the hydrosphere (water), the cryosphere (ice and permafrost), the lithosphere (earth's upper rocky layer) and the biosphere (living things).
Define climate as the statistical characterization of the climate system, representing the average weather, typically over a period of 30 years, and is determined by a combination of processes in the climate system, such as ocean currents and wind patterns.
Explain climate inertia as the phenomenon by which climate systems show resistance or slowness to changes in significant factors e.g. stabilization of greenhouse emissions might show a slow response due to the action of complex feedback systems
Explain that climate change can be categorised into internal variations and external forcings:
- Internal variability can consist of factors that are either cyclical (e.g. the Madden-Jullian oscillation caused by atmospheric circulation and convection) or random (e.g. the ocean and atmosphere can work together to spontaneously generate internal climate variability that can persist for years to decades at a time)
- A change in the energy budget is called a forcing, and when the change is caused by something outside of the five components of the climate system, it is called an external forcing. Volcanoes, for example, result from deep processes within the earth that are not considered part of the climate system. Off-planet changes, such as solar variation and incoming asteroids, are also "external" to the climate system's five components, as are human actions.
Explain how global climate is determined by energy transfer from the Sun with specifc reference to the below factors and terms:
- Recall and use the term Earth energy budget
- Explain how the energy imbalance between the poles and the equator can affect atmospheric circulation
Explain that due to the conservation of angular momentum, the Earth's rotation diverts the air to the right in the Northern Hemisphere and to the left in the Southern hemisphere, thus forming distinct atmospheric cells.
Explain that monsoons, seasonal changes in wind and precipitation that occur mostly in the tropics, form due to the fact that land masses heat up more easily than the ocean. The temperature difference induces a pressure difference between land and ocean, driving a steady wind.
Explain that ocean water that has more salt has a higher density and differences in density play an important role in ocean circulation.
Explain how the thermohaline circulation transports heat from the tropics to the polar regions.
Explain that ocean circulation is further driven by the interaction with wind. The salt component also influences the freezing point temperature. Vertical movements can bring up colder water to the surface in a process called upwelling, which cools down the air above
Explain, with climate systems as examples:
(i) what is a positive feedback cycle
(ii) what is a negative feedback cycle
Explain, using the metaphor of a butterfly's wing flaps may cause hurricanes in another part of the world, how climate science is a an example of a chaotic system (mathematics of chaos theory are not required; just the idea that with very complex systems it is very difficult to predict outcomes and they are very sensitive to initial conditions)
Domain L: Medical Physics
Standard: Students should be able to explain using ray diagrams how the human eye focuses light, and how lenses can be used to correst myopia and hyperopia
Standard: Students should be able to explain how radioactivity and electormagnetic waves can be used in diagnosis of medical conditions
Draw ray diagrams to show the formation of images in the normal eye, a short-sighted eye and a long-sighted eye
Describe the use of converging and diverging lenses to correct long-sightedness and short-sightedness
a. role of rods and cones in the eye, along with the brain, in detecting light and discerning color in combinations of 3 channels (red, green, blue)
b. know that different living organisms may see more and less colors e.g. the mantis shrimp has 12 channels of color and view ultra violet light.
Recall and explain hat a piezo-electric crystal changes shape when a p.d. is applied across it and that the crystal generates an e.m.f. when its shape changes
Explain ow ultrasound waves are generated and detected by a piezoelectric transducer
Explain how the reflection of pulses of ultrasound at boundaries between tissues can be used to obtain diagnostic information about internal structures
define the specific acoustic impedance of a medium as Z = ρc, where c is the speed of sound in the medium
use IR / I0 = (Z1 – Z2)2 /(Z1 + Z2)2 for the intensity reflection coefficient of a boundary between two media
recall and use I = I0e–μx for the attenuation of ultrasound in matter
explain that X-rays are produced by electron bombardment of a metal target and calculate the minimum wavelength of X-rays produced from the accelerating p.d.
Explain the use of X-rays in imaging internal body structures, including an understanding of the term contrast in X-ray imaging
recall and use I = I0e–μx for the attenuation of X-rays in matter
Explain that computed tomography (CT) scanning produces a 3D image of an internal structure by first combining multiple X-ray images taken in the same section from different angles to obtain a 2D image of the section, then repeating this process along an axis and combining 2D images of multiple sections
Explain that a tracer is a substance containing radioactive nuclei that can be introduced into the body and is then absorbed by the tissue being studied
recall that a tracer that decays by β+decay is used in positron emission tomography (PET scanning)
explain that annihilation occurs when a particle interacts with its antiparticle and that mass–energy and momentum are conserved in the process
explain that, in PET scanning, positrons emitted by the decay of the tracer annihilate when they interact with electrons in the tissue, producing a pair of gamma-ray photons travelling in opposite directions
calculate the energy of the gamma-ray photons emitted during the annihilation of an electron-positron pair
Explain that the gamma-ray photons from an annihilation event travel outside the body and can be detected, and an image of the tracer concentration in the tissue can be created by processing the arrival times of the gamma-ray photons
Domain M: Nature of Science
This field studies science’s underlying assumptions, and its methodologies. This involves some integrated study of the history, philosophy and sociology of science.
Standard: Students should be able explain with examples that science operates in a historical context that affects its current practices and paradigms
Benchmark I: Critically analyse claims made about tthe relationship of physics with society
Describe physics as the study of matter, energy, space, time and their mutual connections and interactions
Explain with examples that physics has many sub-fields, and in today’s world involves interdisciplinary fields. Students should be able to distinguish in terms of the broad subject matter that is studied between the below fields:
- Astronomy, Astrophysics, Cosmology
- Classical Mechanics, Quantum Mechanics, Relativistic Mechanics
- Nuclear Physics, Particle Physics
- Cymatics, Acoustics
- Computational Physics
- Climate Physics
Explain with examples how Physics is a subset of the Physical Sciences and of the natural sciences
State examples of essential questions that are important for the branches of Physics they will be studying as part of their curriculum (e.g. for Astrophysics a question would be 'what kinds of heavenly bodies are there in the universe?')
Recognise that scientists who specialise in the research of physics are called Physicists
Recognise that science is a collaborative field that requires interdisciplinary researchers working together to share knowledge and critique ideas
Explain the importance of peer review in quality control of scientific research:
- Scientists spend a considerable amount of time reading the published results of other scientists.
- They publish their own results in scientific journals after a process called peer review. This is when the work of a scientist or, more usually, a team of scientists is anonymously and independently reviewed by several scientists working in the same field who decide if the research methodologies are sound and if the work represents a new contribution to knowledge in that field.
- They also attend conferences to make presentations and display posters of their work.
- Publication of peer-reviewed journals on the internet has increased the efficiency with which the scientific literature can be searched and accessed.
- There are a large number of national and international organizations for scientists working in specialized areas within subjects.
Recall nd use the terms 'hypothesis', 'theory' and 'law' in the context of research in the natural sciences
Explain, with examples of achievements made by scientists in both theoretical and experimental physics, that the 'scientific method' in practice is not a linear process that goes from hypothesis to theory to law
Explain, with examples, the below elements of integrity in scientific work:
- results should not be fixed or manipulated or doctored.
- to help ensure academic honesty and guard against plagiarism, all sources are quoted and appropriate acknowledgment made of help or support.
- All science has to be funded and the source of the funding is crucial in decisions regarding the type of research to be conducted.
Explain that as well as collaborating on the exchange of results, scientists work on a daily basis in collaborative groups on a small and large scale within and between disciplines, laboratories, organizations and countries, facilitated even more by virtual communication. Examples of large-scale collaboration include:
– The Manhattan project, the aim of which was to build and test an atomic bomb. It eventually employed more than 130,000 people and resulted in the creation of multiple production and research sites that operated in secret, culminating in the dropping of two atomic bombs on Hiroshima and Nagasaki.
– The Human Genome Project (HGP), which was an international scientific research project set up to map the human genome. The $3-billion project beginning in 1990 produced a draft of the genome in 2000. The sequence of the DNA is stored in databases available to anyone on the internet.
– The IPCC (Intergovernmental Panel on Climate Change), organized under the auspices of the United Nations, is officially composed of about 2,500 scientists. They produce reports summarizing the work of many more scientists from all around the world.
– CERN, the European Organization for Nuclear Research, an international organization set up in 1954, is the world’s largest particle physics laboratory. The laboratory, situated in Geneva, employs about 2,400 people and shares results with 10,000 scientists and engineers covering over 100 nationalities from 600 or more universities and research facilities.
All the above examples are controversial to some degree and have aroused emotions among scientists and the public.
Explain that scientists often work in areas, or produce findings, that have significant ethical and political implications:
- These areas include nuclear power, artificial intelligence development, exploring asteroids and planets in outerspace through processes like explosions and drilling, and weapons development.
- There are also questions involving intellectual property rights and the free exchange of information that may impact significantly on a society.
- Science is undertaken in universities, commercial companies, government organizations, defence agencies and international organizations. Questions of patents and intellectual property rights arise when work is done in a protected environment.
- Science has been used to solve many problems and improve humankind’s lot, but it has also been used in morally questionable ways and in ways that inadvertently caused problems. Advances in sanitation, clean water supplies and hygiene led to significant decreases in death rates but without compensating decreases in birth rates, this led to huge population increases with all the problems of resources, energy and food supplies that entails.
- Ethical discussions, risk–benefit analyses, risk assessment and the precautionary principle are all parts of the scientific way of addressing the common good.
Differentiate between 'science', 'technology' and 'engineering'. Science is a process of exploring new knowledge methodically through observation and experiments, technology refers to the process of applying scientific knowledge in practical applications for various purposes. Engineering is the application of knowledge in order to design, build and maintain a product or a process that solves a problem and fulfills a need. (something about how science and engineering learn from each other)
History of Physics:
Explain, with examples, that:
a) civilisations across the world have, since before recorded history, studied the workings of natural world.
b) to do science is to be involved in a community of inquiry with certain common principles, methodologies, understandings and processes (these have varied across geographically and historically)
Explain, with examples, that a 'scientific paradigm' is a theoretical model of how nature works
Explain, with examples, Thomas Kuhn's theory of paradigm shifts in the history of physics
Recognise that politics and social inequalities can affect who gets credit for a scientific discovery e.g. historically the contributions of women to scientific research have not been highlighted
Recognise that historically 'modern physics' emerged from the field of 'natural philosophy', and today debates about what is physics and what is metaphysics continues e.g. contestations about fields like String Theory since they do not produce predictions that are experimentally verifiable
Explain, with examples, how:
a) scientific models, some simple, some very complex, based on theoretical understanding, are developed to explain processes that may not be observable.
b) computer-based mathematical models are used to make testable predictions, which can be especially useful when experimentation is not possible.
c) dynamic modelling of complex situations involving large amounts of data, a large number of variables and complex and lengthy calculations is only possible as a result of increased computing power.
d) models can sometimes be tested by using data from the past and used to see if they can predict the present situation. If a model passes this test, we gain confidence in its accuracy
Explain that growth in computing power, sensor technology and networks has allowed scientists to collect large amounts of data:
- Streams of data are downloaded continuously from many sources such as remote sensing satellites and space probes and large amounts of data are generated in gene sequencing machines.
- Research involves analysing large amounts of this data, stored in databases, looking for patterns and unique events. This has to be done using software that is generally written by the scientists involved.
- The data and the software may not be published with the scientific results but would be made generally available to other researchers.
Standard: Students should be able to explain, with examples, what philosophical assumptions underpin the practice of science
Students should able to:
- identify common sources of argumentative fallacies
- explain the broad schools of thought about the relationship between physics and metaphysics
- give examples of ethical dilemmas that emerge from research and practice of science
- explain the broad schools of thought about how science is distinguished from other fields of inquiry
Students should be able to:
- explain the broad schools of thought in debates about the role of beauty in science
- explain how paradoxes and thought experiments help physcists in scientific inquiry
- explain the broad debates about whether it is ethical to continue research in outerspace and of subatomic particles
State that an underlying assumption of science is that the universe has an independent, external reality accessible to human senses and amenable to human reason.
Explain that the importance of evidence is a fundamental common understanding:
a) Evidence can be obtained by observation or experiment. It can be gathered by human senses, primarily sight, but much modern science is carried out using instrumentation and sensors that can gather information remotely and automatically in areas that are too small, or too far away, or otherwise beyond human sense perception.
b) Experimentation in a controlled environment, generally in laboratories, is the other way of obtaining evidence in the form of data, and there are many conventions and understandings as to how this is to be achieved.
State, with examples, how scientists speak of “levels of confidence” (or uncertainty) when discussing experimental outcomes.
Explain and apply the below terms to deconstruct the structure of a scientific argument in a variety of formats such as speeches, written articles and advertisement brochures:
Recognize the below common cognitive biases/fallacies that can hinder sound scientific reasoning:
- the confirmation bias
- hasty generalizations
- post hoc ergo propter hoc (false cause)
- the straw man fallacy
- redefinition (moving the goal posts)
- the appeal to tradition
- false authority
- failing Occam's Razor
- argument from non-testable hypothesis
- begging the question
- fallacy of exclusion
- faulty analogy
Explain, with examples in the context of physics, the differences between induction, deduction and abduction in logic:
- Deductive reasoning is a logical process in which a conclusion is based on the concordance of multiple premises that are generally assumed to be true
- Inductive reasoning is a logical process involving making rational guesses based on data
- Abductive reasoning is inference that goes from an observation to a theory which accounts for the observation, ideally seeking to find the simplest and most likely explanation
Explain the difference between repeatability and reproducibility in physics:
- repeatability as the idea that scientific results from experiments should be possible to verify by conducting the experiment again under the same physical conditions
- reproducibility as the idea that the same or similar result is obtained when the measurement is made under either different conditions or by a different method or in a different experiment
Explain, with examples, that research in physics comes with ethical considerations and implications e.g. animal testing in biophysics, rare earth metals and the environment, nuclear research and possibilities of accidents and misuse of findings
Theory of Knowledge in Physics:
Explain 'empiricism' as the idea that all knowledge is derived from sense-experience. Connect this with the philosophical view that evidence from the empirical world is more reliable than mathematical projection.
Explain 'rationalism' as the idea that knowledge should take precedent from reasoning, not sense-experience. Connect this with the philosophical view that mathematics is more reliable than the impressions made from empirical world.
Differentiate between the philosophical views of scientific determinism (that everything can be predicted through calculation if all the physical conditions are known), indeterminism (that everything occurs as a matter of probability) and theological determinism (that there is a diety or dieties that determine every event that occurs in the past, present and future of the world)
Differentiate between reductionism and holism in the context of science as:
a- reductionism as the view that complex interactions and entities can be reduced to the sum of their constituent parts
b- holism as the view idea that all the properties of a given system cannot be determined or explained by its component parts alone. Instead, the system as a whole determines in an important way how the parts behave.
Differentiate between positivism and postpositivism in the context of science as:
- positivism is the view of science that holds that every rationally justifiable assertion can be objectively scientifically verified or is capable of logical or mathematical proof
- postpositivism is an amended view of positivism that holds that that theories, hypotheses, background knowledge and values of the researcher can influence what is observed e.g. the cycle of day and night can seem like proof of either heliocentrism (view that the earth goes around the sun) or geocentrism (view that the sun goes around the earth)
Explain Occam’s Razor (principle of parsimony) as the belief that the simplest explanation is the ideal one; the one with the fewest assumptions
Explain falsifiability as the idea that a theory is scientific only if it makes assertions that can be disproven
Explain, with examples, that scientists analyse data and look for patterns, trends and discrepancies, attempting to discover relationships and establish causal links. This is not always possible, so identifying and classifying observations and artefacts (eg types of galaxies or fossils) is still an important aspect of scientific work.
Explain, with examples from Physics, that a thought experiment is a hypothetical situation in which a hypothesis, theory, or principle is laid out for the purpose of thinking through its consequences
Explain how the below thought experiments helped convey important physics concepts, why they would be impractical to conduct emperically:
(i) Netwon's canonball
(ii) Einstein's teenager chasing a beam of light
Explain, with reference to the below examples, that a paradox is a statement that, despite apparently valid reasoning from true premises, leads to a seemingly self-contradictory or a logically unacceptable conclusion:
(i) The Grandfather paradox
(ii) Achilles and the tortoise
Philosophy of Quantum Mechanics:
Explain, with the context of the electron diffraction double slit experiment, explain the below two of the many interpetations of quantum mechanics:
(i) copehagen interpretation
(ii) many worlds interpretation
Debates about Beauty in Physics:
Explain, with examples, what do thinkers who hold the view that there is inherent mathematical beauty in the natural world mean by:
(i) elegance or simplicity
Explain, with an example, a counterargument to the claim that physical truths must be inherently mathematically elegant or display symmetry
Describe the main pros and cons in the debate about:
(i) whether humans should research whether there are aliens somewhere in the universe
(ii) whether research should continue on uncovering the secrets of subatomic particles, given the advent of nuclear weapons
Experimentation Skills Progression Grid
It is assumed that students will already have knowledge (and be able to apply it as needed in their current class) of what they learnt in their previous grades, so SLOs from previous grades are not repeated in the higher grades. In practice teachers may want to refresh concepts with their students as appropriate.Note 2: Teachers and schools are free to switch around SLOs among Grades 9 and 10 according to their teaching preferences. Similarly they are free to switch around SLOs among Grades 11 and 12 with each other.
Domain N: Experimentation Skills
These cover the skills that are necessary for understanding how design and practically conduct physics experiments. These skills are not meant to be applied not only in the science lab, but as skills of critical analysis for understanding empirical data as well.
Standard: Students should be able to demonstrate knowledge of how to select and safely use techniques, apparatus and materials
Benchmark I: Students should be able to follow provided safety instructions and take general precautions in a lab setting
Benchmark I: Students should be able to identify and take the safety measures required to conduct experiments
Benchmark I: Students should be able to design safe experiments
- explain, with examples, how hazards in a science lab can be classified into:
(i) physical hazards
(ii) chemical hazards
(iii) biological hazards
(v) safety hazards
- identify for a given experimental procedure what would be the most appropriate personal protective equipment to wear before setting up the apparatus
- recognise the meaning of common hazard signs in the laboratory
- call emergency services in case of an accident in the lab
- test that the lab equipment is functioning properly, without any potential risk of injury, before conducting an experiment
- ensure that work space for conducting the experiment is not too crowded with apparatus as to be hazardous[SLO: P-11-N-03]
- ensure that safe distance is kept at all times from other investigators who may be handling lab apparatus
- suggest broadly what potential bodily harm could occur from physical, chemical, biological and safety hazards in the context of the experiment being conducted
- recognise that it is always better to ask for help from the lab instructor when unsure of how to use new apparatus
- develop and justify safety guidelines for a proposed procedure, that also outline the overall risks of the experiment, keeping in mind:
(i) the apparatus
(ii) the surrounding environment
(iii) need for personal protective equipment
Standard: Students should be able to plan experiments and investigations
Benchmark I: Create an outline of how to conduct an experiment to compare a given dependent variable and independent variable
Benchmark I: Create an outline of a complete experimental design for a formulated hypothesis
Define and use the below terms:
- True value: the value that would be obtained in an ideal measurement
- Measurement error: the difference between a measured value and the true value of a quantity
- Accuracy: a measurement result is described as accurate if it is close to the true value
- Precision: how close the measured values of a quantity are to each other
- Repeatability: a measurement is repeatable if the same or similar result is obtained when the measurement is repeated under the same conditions, using the same method, within the same experiment
- Reproducibility: a measurement is reproducible if the same or similar result is obtained when the measurement is made under either different conditions or by a different method or in a different experiment
- Validity of experimental design: an experiment is valid if the experiment tests what it says it will test. The experiment must be a fair test where only the independent variable and dependent variable may change, and controlled variables are kept constant
- Range: the maximum and minimum value of the independent or dependent variables
- Anomaly: an anomaly is a value in a set of results that appears to be outside the general pattern of the results, i.e. an extreme value that is either very high or very low in comparison to others
- Independent variables: independent variables are the variables that are changed in a scientific experiment by the scientist. Changing an independent variable may cause a change in the dependent variable
- Dependent variables: dependent variables are the variables that are observed or measured in a scientific experiment. Dependent variables may change based on changes made to the independent variables
- identify appropriate apparatus for collecting the data
- visualize how the collected data would be tabulated or graphed
- explain step by step the methodology for analysing the data (e.g. gradient of line of best fit, plugging average value of dependent variable into a formula etc.)
- suggest how sources of human and systematic error could be mitigated
Formulate a testable hypothesis by:
• identifying the independent variable in the experiment
• identifying the dependent variable in the experiment
• identifying the variables that are to be kept constant.
Explain the methods of data collection by:
a• describing the method to be used to vary the independent variable
b• describing how the independent and dependent variables are to be measured
c• describing how other variables are to be kept constant
d• describing, with the aid of a clear labelled diagram, the arrangement of apparatus for the experiment and the procedures to be followed.
Explain the methods of data analysis by:
a• describing how the data should be used in order to reach a conclusion, including details of derived quantities to be calculated from graphs.[SLO: P-12-N-05]
Suggest how technology can be used to digitse data collection by describing as appropriate:
a• the use of an oscilloscope (or storage oscilloscope) to measure voltage, current, time and frequency
b• how to use light gates connected to a data logger to determine time, velocity and acceleration
c• how other sensors can be used with a data logger, e.g. motion sensor.
Standard: Students should be able to make and record observations, measurements and estimates
Benchmark I: Collect data under instructor supervision while minimising sources of random and systematic error
Benchmark I: Collect data without supervision while minimising sources of random and systematic error
- set up experimental apparatus under supervision from an instructor
- take steps to avoid parallex error
- identify and correct for potential zero error
- take an appropriate number of readings to average out errors
- take correct meniscus readings
- record sources of potential error (e.g. lack of lighting due to power outage)
- take steps to avoid systematic error in specific context of the experiment e.g. ensuring that the table the set-up in on is level
- make measurements using common laboratory apparatus, such as millimetre scales, protractors, top-pan balances, newton meters, analogue or digital electrical meters, measuring cylinders, vernier calipers, micrometer screw gauges and thermometers
- use a stop-watch to measure intervals of time, including the period of an oscillating system by timing an appropriate number of consecutive oscillations
- use both analogue scales and digital displays.
- Be familiar with the following experimental contexts:
• measurement of physical quantities such as length, volume or force
• measurement of small distances or short intervals of time
• determining a derived quantity such as the extension per unit load for a spring, the value of a known resistance or the acceleration of an object
• testing and identifying the relationship between two variables such as between the potential difference across a wire and its length
• comparing measured quantities such as angles of reflection
• comparing derived quantities such as density
• cooling and heating, including measurement of temperature
• experiments using springs and balances
• timing motion or oscillations
• electric circuits, including the connection and reconnection of these circuits, and the measurement of current and potential difference
• optics experiments using equipment such as optics pins, mirrors, prisms, lenses, glass or Perspex blocks (both rectangular and semi-circular), including the use of transparent, translucent and opaque substances to investigate the transmission of light
• procedures using simple apparatus, in situations where the method may not be familiar to the candidate.
• set up apparatus correctly without assistance from a supervisor
• follow instructions given in the form of written instructions and diagrams (including circuit diagrams)
• use apparatus to collect an appropriate quantity of data
• repeat readings where appropriate
• make measurements that span the largest possible range of values within the limits either of the equipment provided or of the instructions given.
Benchmark II: Tabulate and graph data appropriately
Benchmark II: Tabulate and graph data appropriately, including use of false origins
Benchmark II: Tabulate and graph data appropriately, including use of false origins and tabulating uncertainty estimates
Use the below good practices in tabulating data:
- Record measured and calculated quantities with correct units accompaying them
- Organise tabulated results with the following elements present: the heading of each column, the name or symbol of the measured or calculated quantity, together with the appropriate unit.
Use the below good practices in drawing graphs:
- Label axes with quantities and units
- Use scales for the axes that allow the majority of the graph paper to be used in both directions, and be based on sensible ratios, e.g. 2cm on the graph paper representing 1, 2 or 5 units of the variable (or 10, 20 or 50, etc.).
- Plot data points to an accuracy of better than one half of one of the smallest squares on the grid.
- Plot data points using small crosss or fine dots with a circles drawn around them.
• use a false origin where appropriate while plotting graphs
• show uncertainty estimates, in absolute terms, beside every value in a table of results
Benchmark III: Estimate data collected to an appropriate number of significant figures and decimal points
Benchmark III: Estimate data collected to an appropriate number of significant figures and with the uncertainty quoted
Benchmark III: Estimate data collected to an appropriate number of significant figures, with the uncertainty quoted and express graphically with error bars and lines of best and worst fit
- Use measuring instruments to their full precision
- Estimate the number of significant figures for calculated quantities as being the same as the least number of significant figures in the raw data used.
• estimate the absolute uncertainty in measurements
• express the uncertainty in a measurement as an absolute or percentage uncertainty, and translate between these forms
• express the absolute uncertainty in a repeated measurement as half the range of the repeated readings, where this is appropriate.
• show error bars, in both directions where appropriate, for each point on the graph
• draw a straight line of best fit and a worst acceptable straight line through the points on the graph.
Standard: Students should be able to interpret and evaluate experimental observations and data
Benchmark I: Analyse plotted linear graphs and tables
Benchmark I: Analyse tablular data, plotted linear and polynomial graphs for how well they fit with the hypothesised theoretical relationship the studied variables by consdering the calculated values obtained and their corresponding percentage uncertainty
Benchmark I: Analyse tablular data, plotted linear, polynomial, exponential and logarithmic graphs for how well they fit with the hypothesised theoretical relationship the studied variables by consdering the calculated values obtained and their corresponding percentage and absolute uncertainty
- Show clear working in calculations, and key steps in reasoning
- Express calculated ratios as decimal numbers, of two or three significant figures.
- Sketch lines of best fit with an equal number of points on either side of the line over its entire length (the points should not be seen to lie all above the line at one end, and all below the line at the other end)
- Convey the calculations for the gradient of a straight line by using a triangle whose hypotenuse extends over at least half the length of the plotted graph line.
- Determine the intercept of a straight line graph
- Take readings from graphs by extrapolation or interpolation
• draw straight lines of best fit or curves to show the trend of a graph
• draw tangents to curved trend lines.
• relate straight-line graphs to equations of the form y = mx + c, and derive expressions that equate to the gradient and/or the y-intercept of their graphs
• read the coordinates of points on the trend line of a graph
• determine the gradient of a straight-line graph or of a tangent to a curve
• determine the y-intercept of a straight-line graph or of a tangent to a curve, including where these are on graphs with a false origin.
• draw conclusions from an experiment, including determining the values of constants
• explain whether experimental data supports a given hypothesis and make predictions based on the data
• determine whether a relationship containing a constant is supported by experimental data
• for results of an experiment:
(i) calculate the percentage difference between values of the constant
(ii) compare this percentage difference with a pre-given percentage uncertainty
(iii) give a conclusion based on this comparison.
• rearrange expressions into the forms y = mx + c, y = axn and y = aekx
• understand how a graph of y against x is used to find the constants m and c in an equation of the form y = mx + c
• understand how a graph of log y against log x is used to find the constants a and n in an equation of the form y = axn
• understand how a graph of ln y against x is used to find the constants a and k in an equation of the form y = aekx
• decide what derived quantities to calculate from raw data in order to enable an appropriate graph to be plotted.
• convert absolute uncertainty estimates into fractional or percentage uncertainty estimates and vice versa
• calculate uncertainty estimates in derived quantities
• estimate the absolute uncertainty in the gradient of a graph by recalling that absolute uncertainty = gradient of line of best fit – gradient of worst acceptable line
• estimate the absolute uncertainty in the y-intercept of a graph by recalling that absolute uncertainty = y-intercept of line of best fit – y-intercept of worst acceptable line
• express a quantity as a value, an uncertainty estimate and a unit.
Standard: Students should be able to evaluate methods and suggest possible improvements
Evaluate and suggest improvements regarding whether an experimental design:
- is valid and reliable
- has sources of error that could be better mitigated
- is safe to conduct
Benchmark I: Evaluate and suggest improvements regarding whether an experimental design could improve on the uncertainty in its conclusions
- Identify whether an experimental procedure has validity (whether the results really do represent what they are supposed to measure) regarding the hypothesis being tested, and suggest changes to ensure validity as appropriate
- identify whether an experimental procedure is reliable (whether the results can be reproduced under the same conditions), and suggest changes to ensure reliability as appropriate
- recommend how to mitigate sources of random and systematic error inherent in the given experimental design
- identify unsafe procedure in an experimental design and suggest ways to mitigate any hazards
• identify and describe the limitations in an experimental procedure
• identify the most significant sources of uncertainty in an experiment.
• suggest modifications:
- an experimental arrangement that will improve the accuracy of the experiment or to extend the investigation to answer a new question
- describe these modifications clearly in words or diagrams.