| A | B |
|---|
| frame of reference | a system of objects that are not moving with respect to one another |
| relative motion | movement in relation to a frame of reference |
| distance | the length of a path between two points |
| vector | a quantity that has magnitude and direction |
| resultant vector | the vector sum of two or more vectors |
| speed | the ratio of the distance an object moves to the amount of time the object moves |
| average speed | the total distance traveled divided by the time it takes to travel that distance |
| instantaneous speed | the rate at which an object is moving at a given moment in time |
| velocity | the speed and direction in which an object is moving |
| acceleration | the rate at which velocity changes |
| free fall | the movement of an object toward Earth solely because of gravity |
| constant acceleration | a steady change in velocity |
| linear graph | a graph in which the displayed data form straight-line parts |
| nonlinear graph | a curve connect the data points that are plotted |
