| A | B |
|---|
| position | describes the location of an object |
| reference point | a location to which you compare other locations |
| motion | the change of position over time |
| speed | a measure of how fast something moves or the distance it moves, in a given amount of time |
| velocity | speed in a specific direction |
| vector | a quantity that has both size and direction |
| acceleration | the rate at which velocity changes with time |
| force | a push or a pull / like velocity, force is a vector (has size and direction) |
| contact force | when one object pushes or pulls another object by touching it |
| gravity | the force of attraction between two masses |
| friction | a force that resist 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 remain at rest or in motion with the same velocity, unless acted upon by an unbalanced force |
| inertia | the resistance of an object to a change in the speed or the direction of its motion |
| Newton's Second Law | the acceleration of an object increases with increased force and decreases with an increased mass |
| centripetal force | any force that keeps an object moving in a circle |
| Newton's Third Law | states that every time one object exerts a force on another object, the second object exerts a force that is equal in size and opposite in direction back on the first object |
| momentum | a measure of mass in motion; the momentum of an object is the product of its mass and its velocity |
| conservation of momentum | the total momentum of a system of objects doesn't change, as long as no outside forces are acting on that system |
| collision | a situation in which two objects in close contact exchange energy and momentum |
