| A | B |
|---|
| non-contact force | a force that acts at a distance |
| gravity | a force of attraction between any two objects |
| balanced | equal forces that combine to act on an object in opposite directions |
| average speed | the measure of how fast an object is moving during a certain amount of time |
| force | a push or pull that acts on an object |
| contact force | a force that requires two pieces of matter to touch |
| potential energy | energy that is not causing any changes now but could cause changes in the future |
| acceleration | the rate at which the speed or direction of motion of an object changes over time |
| kinetic energy | energy due to motion |
| inertia | the tendency of an object to resist any change in motion |
| shadow | an area of partial darkness where light has been blocked by an object |
| energy | ability to do work or cause change |
