| A | B |
|---|
| motion | a change in position |
| elapsed time | length of time that passes from one event to another |
| speed | rate at which the position of an object changes |
| acceleration | a change in speed or direction |
| 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 the path between two points |
| displacement | the direction from the starting point and the length of a straight line from the starting point to the ending point |
| vector | a quantity that has magnitude and direction |
| resultant vector | the vector sum of two or more vectors |
| average speed | the total distance traveled divided by the time that 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 |
| free fall | the movement of an object toward Earth solely because of gravity |
| constant acceleration | a steady change in velocity |
| linear graph | the displayed data form straight-line parts |
| nonlinear graph | a curve connects the data points that are plotted |
| quadratic relationship | exists when one variable depends on the square of another |
| inverse relationship | results when one variable depends on the inverse of the other |
| coordinate system | a system used to describe motion that gives the zero point location of the variable being studied and the direction in which the values of the variable increase |
| position | the separation between an object and the origin |
| magnitude | a measure of size |
| scalar | a quantity that has only magnitude and no direction |
| gravitational acceleration | acceleration of an object in free fall that results from the influence of the Earth’s gravity; equal to 9.80 m/s^2 |
