| A | B |
|---|
| position | the location of a place or object |
| reference point | a location to which you compare other locations |
| motion | change in position over time |
| speed | measure of how fast something moves or the distance it moves in a given amount of time |
| velocity | speed in a specfic direction |
| vector | a quantity that has both size and direction |
| acceleration | the rate at which velocity changes with time |
| force | a push or pull |
| contact force | a force that is applied when one object pushes or pulls another object by touching it |
| gravity | the force of attraction between two masses |
| friction | a force that resists the motion between two surfaces that are pressed together |
| net force | the overall force acting on an object when all the forces are combined |
| Newton's first law | objects at rest remain at rest and objects in motion remain in motion at the same velocity, unless acted upon by an unbalanced force. |
| inertia | the resistance of an object a change in the speed or direction of its motion |
| Newton's second law | the acceleration of an object increases with increased force and decreases with increased mass (F=ma) |
| centripetal force | any force that keeps an object moving in a circle |
| Newton's third law | forces act in pairs (for every action thers is an equal and opposite reaction) |
