Chapter P4 - Explaining Motion


  • Describing motion - speed, velocity, acceleration, distance-time graphs, speed-time graphs; displacement-time graphs, velocity-time graphs.
  • Forces - Newton's laws, interaction pairs, resultant forces, how forces affect motion, momentum
  • Work and energy - work done, gravitational potential energy, kinetic energy


Measuring Speed and Distance Time Graphs

  • Click here for my some excellent powerpoints on forces and motion from Staffordshire Learning Net.
  • Click here for Usain Bolt's 100m Beijing world record on youtube.
  • Click here for PheT's Moving Man simulation - to explore displacement-time and velocity-time graphs.

Newton's Three Laws of Motion

  1. An object will not accelerate (speed up, slow down or change direction) if there is NO resultant force on it.
  2. If an object experiences a resultant force, then it accelerates - its acceleration is proportional to the force and inversely proportional to the mass of the object.
  3. Forces come in pairs - if A exerts a force on B in one direction, then B exerts a force on A in the opposite direction; the force is the same size and the same type.

Physics Tracker Software

Click here to download "Physics Tracker" software. I use this to analyse regular and high speed video of experiments we do in class.

photo bar of physics images

© 2010 Ally Davies  Cambridge UK  Bookmark and Share Follow myPhysicsorguk on Twitter