| A | B |
|---|
| frame of reference | stationary background used to describe motion |
| motion | change in position over a certain amount of time |
| speed | distance divided by time |
| velocity | speed in a given direction |
| acceleration | the rate of change in velocity |
| momentum | mass times velocity |
| force | push or pull that gives energy to an object |
| friction | a force that acts in an opposite direction of motion |
| inertia | property that resists change in motion |
| newton | the unit of force |
| gravity | force of attraction between 2 objects |
| Law of Universal Gravitation | states that all object attract each other by gravity |
| deceleration | slowing down, negative acceleration |
| balanced forces | forces in opposite directions and equal in size |
| unbalanced forces | forces in opposite directions and unequal in size |
| weight | a measure of the pull of gravity on an object |
| air resistance | the opposing force of air |
| conservation of momemtum | momentum is neither lost nor gained, stays the same |
