3.03h third law h) Understand and be able to use third law. l) Be able to extend use of third law to MR4 Newton’s Newton’s Newton’s 3.03l situations where forces need to be resolved (restricted Every action has an equal and opposite reaction. to two dimensions). Learners should understand and be able to use the concept that a system in which none of its components have any relative motion may be modelled as a single particle. 3.03i i) Understand and be able to use the concept of a normal reaction force. Learners should understand and use the result that when an object is resting on a horizontal surface the normal reaction force is equal and opposite to the weight of the object. This includes knowing that when contact is lost. 3.03j j) Be able to use the model of a contact and ‘smooth’ understand the limitations of the model. 3.03k k) Be able to use the concept of equilibrium together m) Be able to use the principle that a particle is in 3.03m with one dimensional motion in a straight line to solve equilibrium if and only if the sum of the resolved parts problems that involve connected particles and smooth in a given direction is zero. pulleys. Problems may involve the resolving of forces, e.g. A train engine pulling a train carriage(s) along a including cases where it is sensible to: straight horizontal track or the vertical motion of two 1. resolve horizontally and vertically, particles, connected by a light inextensible string 2. resolve parallel and perpendicular to an inclined passing over a fixed smooth peg or light pulley. plane, 3. resolve in directions to be chosen by the learner, or 4. use a polygon of forces.
3.03h 3.03l 3.03i 3.03j 3.03k 3.03m Newton’s third law h) Understand and be able to use Newton’s third law. Every action has an equal and opposite reaction. Learners should understand and be able to use the concept that a system in which none of its components have any relative motion may be modelled as a single particle. i) Understand and be able to use the concept of a normal reaction force. Learners should understand and use the result that when an object is resting on a horizontal surface the normal reaction force is equal and opposite to the weight of the object. This includes knowing that when contact is lost. j) Be able to use the model of a ‘smooth’ contact and understand the limitations of the model. k) Be able to use the concept of equilibrium together with one dimensional motion in a straight line to solve problems that involve connected particles and smooth pulleys. e.g. A train engine pulling a train carriage(s) along a straight horizontal track or the vertical motion of two particles, connected by a light inextensible string passing over a fixed smooth peg or light pulley. l) Be able to extend use of Newton’s third law to situations where forces need to be resolved (restricted to two dimensions). m) Be able to use the principle that a particle is in equilibrium if and only if the sum of the resolved parts in a given direction is zero. Problems may involve the resolving of forces, including cases where it is sensible to: 1. resolve horizontally and vertically, 2. resolve parallel and perpendicular to an inclined plane, 3. resolve in directions to be chosen by the learner, or 4. use a polygon of forces. MR4
418253-section-3.03-forces-and-newton-s-laws-delivery-guide.docx