| A | B |
|---|
| motion | change in position |
| speed | distance traveled per unit of time |
| velocity | speed and direction |
| acceleration | any change in speed or direction |
| balanced forces | forces that are equal in size but opposite in direction |
| force | a push or pull |
| unbalanced forces | forces that cause a change in the motion of an object |
| inertia | the tendency of an object to stay at rest or in motion |
| newton | unit of force equal to 1 kilogram-meter per second per second |
| action force | force acting in one direction |
| reaction force | force acting in the opposite direction |
