| A | B |
|---|
| motion | when an object's distance from another object is changing |
| reference point | a place or object used for comparison to determine if something is in motion |
| International system of Units (SI) | a system of measurement based on the number ten |
| meter | the basic SI unit of length |
| speed | the distance an object travels per unit of time |
| speed = | distance divided by time |
| velocity | speed in a given direction |
| plates | the 12+ major pieces that the upper layer of Earth consists of |
| acceleration | the rate at which |
