| A | B |
|---|
| force | a push or pull |
| balanced | forces are equal and opposite each other |
| unbalanced | one force must be greater than the force that opposes motion |
| work | the product of the force applied to an object and the distance the object moves |
| joule | the unit for work |
| machine | makes work easier by changing the direction or distance through which a force moves |
| mechanical advantage | the amount by which a machine increases a force |
| friction | a force that opposes motion |
| lever | a bar that is free to turn about a fixed point |
| fulcrum | the point at which a lever rotates |
| effort arm | the distance from the fulcrum to the effort force |
| resistance arm | the distance from the fulcrum to the resistance force. |
| resistance force | weight of the object the lever will move |
| mechanical advantage | the amount by which a lever increases a force |
| radius | distance from the center to the edge of a wheel |
| inclined planes | a slanted surface used to raise objects |
| wedge | made of two inclined planes |
| efficiency | the ratio of work output to work input |
| Power | the amount of work done per unit of time |
| watt | the unit for power |
