| A | B |
|---|
| speed | a rate of motion or rate of change over time |
| instantaneous speed | a rate of motion in a given instant |
| constant speed | a rate of motion does not change |
| average speed | the rate of motion varies - total distance divided by total time |
| velocity | the speed and direction of a moving body |
| acceleration | the rate of change in velocity |
| force | a push or pull one body exerts on another |
| balanced forces | forces that are equal in size and opposite in direction |
| net force | sum of forces on an object |
| inertia | tendency of an object to resist a change in motion |
| friction | the force between two surfaces that opposes motion |
| gravity | the force exerted by every object in the universe on every other object |
| weight | measure of the force of gravity on an object |
| motion | change in position of an object |
