| A | B |
|---|
| average speed | total distance traveled divided by time |
| rate | an expression in which the denominator is time |
| acceleration | the rate at which speed or direction changes |
| force | a push or a pull |
| weight | the downward force of gravity on a mass |
| normal force | the upward force of the ground |
| Newton | a measure of force |
| inertia | the measure of an object's ability to stay at rest or to keep moving |
| mass | the amount of matter in an object |
| Newton's first law of motion | States that "an object at rest will remain at rest or an object in moviton will remain in motion until acted upon by an unbalanced force." |
| Newton's second law of motion | An object that has an unbalanced force acting on it will accelerate in the direction of the force. |
| Newton's third law of motion | Forces always occur in equal but opposite pairs. |
| friction | a force that resists motion between two objects in contact. |
