| A | B |
|---|
| motion | An objects change in position relative to a reference point. |
| speed | The distance traveled divided by the time interval during which the motion occurred. |
| average speed | total distance divided by total time |
| velocity | The speed of an object in a particular direction. |
| acceleration | The rate at which velocity changes over time: an object accelerates if its speed, direction, or both change. |
| Combine two velocities in same direction = | add them together to find resultant velocity. |
| Combine two velocities in opposite directions = | subtract the smaller from the larger velocity to find the resultant velocity. |
| average acceleration = | final velocity - starting velocity divided by time it takes to change velocity. |
| centripetal acceleration | acceleration occurring in circular motion. |
| force | a push or pull exerted on an object in order to change the motion of the object; force has size and direction |
| newton | the SI unit for force ( symbol N ) |
| net force | the combination of all of the forces acting on an object. |
| friction | a force that opposes motion between two surfaces that are in contact. |
| gravity | a force of attraction between objects that is due to their masses. |
| The Law of Universal Gravitation | gravitational force increases as mass increases and gravitational force decreases as distance increases. |
| weight | a measure of the gravitational force exerted on an object; its value can change with location of the object in the universe. |
| mass | a measure of the amount of matter in an object. |
