dynamics 1.3

• newtons third law


  if body A exerts a force on body B, body B will exert an equal and opposite force on body A
• newtons second law


  force is equal to the rate of change of momentum
• elastic collision


  kinetic energy before colliding is equal to the kinetic energy after
• inelastic collision


  kinetic energy before the collision is not equal to the kinetic energy after after a collision
• conservation of momentum


  the vector sum of the momenta of bodies in a system stays constant even if forces act between the bodies, provided there is no external resultant force