| A | B |
|---|
| force | a push or pull on an object |
| friction | force that acts in the opposite direction of motion |
| frame of reference | object with which movement is compared |
| motion | change in position in a certain amount of time |
| speed | rate at which an object moves |
| velocity | description of speed in a given direction |
| acceleration | rate of change in velocity |
| momentum | mass of an object times its velocity |
| constant speed | speed that does not change |
| average speed | determined by dividing total distance by total time |
