text: # Physics - Mechanics
  
  ?
  
  ## Mechanics - Kinematics 2.1.1
  
  • Displacement - Distance travelled in a particular direction.
  • Velocity - Distance travelled in a certain direction in 1 second.
  • Speed - Distance travelled in 1 second.
  • Acceleration - The change in velocity in 1 second.
  1 of 5
  
  ## Mechanics - Kinematics 2.1.2
  
  • Instantaneous values of speed, velocity and acceleration is the value at a single moment in time, not over a period of time. Average values of all three are the average values of the speed/velocity/acceleration over a certain period of time, not just a single moment.
  
  • Average velocity is the difference between the beginning and the end.
  e.g. distance = 16km, journey time = 4 hours
  average velocity = 16/4
  = 4 km h^-1
  • Average velocity = displacement/time
  
  • Average speed = distance/time
  
  • Average acceleration = change in velocity/change in time
  unit of acceleration is m s^-2
  Acceleration is a vector quantity
  2 of 5
  
  ## Mechanics - Kinematics 2.1.3
  
  • The equations of uniformly accelerated motion can only be under conditions where the acceleration is constant.
  • SUVAT used for uniformly accelerated motion:
  • v = u + at
  • s = (u + v/2) t
  • v^2 = u^2 + 2as
  • s = ut + 1/2at^2
  • s = vt - 1/2at^2
  3 of 5
  
  ## Mechanics - Kinematics 2.1.6
  
  • Air resistance eventually affects all objects that are in motion. Due to the effect of air resistance objects can reach terminal velocity. This is a point by which the velocity remains constant and acceleration is zero.
  • In the absence of air resistance all objects have the same acceleration irrespective of its mass.
  4 of 5
  
  ## Physics
  
  • Instantaneous velocity is how fast it’s going at that moment in time and in which direction.
  • Average velocity is the difference between the beginning and the end.
  e.g. distance = 16km, journey time = 4 hours
  average velocity = 16/4
  = 4 km h^-1
  • average velocity = displacement/time
  • Instantaneous velocity = length/time for object to pass
  • Acceleration = change of velocity/time
  unit of acceleration is m s^-2
  Acceleration is a vector quantity
  5 of 5
  
  ## Comments
  
  No comments have yet been made
  
  ## Similar Physics resources:
  
  See all Physics resources »See all Motion resources »