| A | B |
|---|
| horizontal | parallel to the horizon; level. |
| meter | The international standard unit of length, about 39.37 inches. |
| second | A unit of time equal to one-sixtieth of a minute. |
| vertical | Going straight up or down from a level surface. |
| position | An object's location. |
| reference point | A location to which another locationis compared. |
| motion | A change of postion over time. |
| speed | A measure of how fast something moves through a particular distance over a definite time period. Distance divided by time. |
| velocity | A speed in a specific direction. |
| vector | A quantity that has both size and direction. |
| acceleration | The rate at which velocity changes over time. |
