| A | B |
|---|
| average speed | distance traveled divided by the time it takes to travel this distance |
| acceleration | rate at which speed or direction changes |
| rate | ratio of two measurements with different units |
| gravity | attraction between all matter; a force that pullson all objects that have mass. |
| force | a push or pull; can be measured by the amount of acceleration it can give a mass |
| weight | downward pull of gravity on an object |
| normal force | upward force of the ground, perpendicular to the surface |
| balanced forces | describes forces acting on an object that cancel each other out. |
| inertia | measure of an object's ability to remain at rest or to keep moving. |
| mass | amount of matter in an object |
| friction | force that resists motion between two objects in contact and always acts opposite to the direction of the motion |
