| A | B |
|---|
| average speed | equals the distance traveled divided by the amount of time it takes to travel that distance. |
| instantaneous speed | speed of an object at any given time. |
| velocity | speed of an object and its direction of motion; changes when speed changes, direction of motion changes, or both. |
| acceleration | change in velocity divided by the time needed for the change to occur. |
| force | push or pull. |
| Newton's laws of motion | set of rules developed by Isaac Newton to explain how forces affect the motion of an object. |
| friction | force between two surfaces in contact that resists the motion of the surfaces past each other. |
| inertia | tendency to resist a change in motion. |
| work | is done when an applied force causes an ojbect to move in the direction of the force. |
| simple machine | machine that uses only one movement. |
| compound machine | a machine that is a combination of simple machines. |
| mechanical advantage | the number of times the applied force is increased by a machine. |
| pulley | grooved wheel with a rope or cable running through the groove. |
| lever | rod or plank that pivots about a fixed point. |
| inclined plane | a sloped surface or a ramp that allows you to lift a heavy load by using less force over a greater distance. |
