| A | B |
|---|
| velocity | speed and direction |
| speed | how fast |
| positive acceleration | speeding up |
| negative acceleration | slowing down |
| friction | force between two surfaces |
| gravity | force exerted by an object on every other object |
| rate | change over time |
| inertia | resistance to motion |
| Newton's first law | an object will stay at rest or in motion unless acted on by a net force |
| balanced forces | equal in size and opposite in direction |
| unbalanced forces | unequal in size |
| physical science | study of matter and energy |
| distance/time | speed |
| scalar quantity | number registered on a scale |
| vector quantity | number that includes direction |
| constant speed | speed that does not vary |
| instantaneous speed | speed at a particular moment in time |
| average speed | the sum of all the instantaneous speeds divided by time |
| gravity | directly related to object's weight |
| change in velocity | used to calculate acceleration |
