| A | B |
|---|
| Relative motion | change in position of one object compared to the position of some fixed object |
| frame of reference | the objects you use to detect motion |
| speed | the rate at which an object's position changes |
| velocity | the speed and the direction an object is moving |
| force | any push or pull |
| friction | force that acts when two surfaces rub together |
| gravity | force that makes objects pull toward each other |
| work | using force in order to move an object a certain distance |
| kinetic energy | energy of motion |
| potential energy | stored energy |
