| A | B |
|---|
| speed | the rate of change in position |
| motion | a change in position |
| instantaneous speed | the rate of motion at any given instant |
| constant speed | a speed that does not vary |
| average speed | total distance traveled divided by total time of travel |
| meter per second | unit of velocity |
| velocity | describes both speed and direction |
| acceleration | the rate of change of velocity |
| average acceleration | the change in velocity divided by the time interval |
| force | a push or a pull one body exerts on another |
| balanced forces | forces that are equal in size and opposite in direction |
| inertia | the tendency of an object to resist any change in motion |
| Newton's First Law of Motion | an object moving at a constant velocity keeps moving at that velocity unless a net force acts on it |
| friction | the force that opposes motion between two surfaces that are touching each other |
| gravity | every object in the universe exerts a force on every other object |
| affects gravitational force | mass and distance between them |
| weight | the measure of the force of gravity on an objects |
| scale | uses the principle of balanced forces to measure how much something weighs |
| October 25 | Britanya's birthday |
