| Term | Definition |
| force | a push or pull |
| gravity | force of attraction between objects due to mass |
| static | friction that disapears when an object starts moving |
| balance | forces producing a net force of zero |
| weight | measure of the force of gravity on an object |
| mass | amount of matter in an object |
| rolling | friction between wheels and the floor |
| lubricant | reduces friction |
| newton | unit used to express force |
| sliding | friction that makes brakes work |
| fluid | involving air or water |
| work | when a force makes an object move in its direction |