| A | B |
|---|
| pulley | made up of a grooved wheel over which a rope passes |
| lever | a long, rigid bar with a support |
| inclined plane | a flat surface with one end higher than the other |
| wedge | an inclined planw with either one or two sloping sides |
| screw | a spiral inclined plane |
| wheel and axle | a special kind of lever that is used to move a load for a farther distance |
| mechanical advantage | the number of times a machine increases an applied force |
| machine | changes the direction of an applied force |
| friction | decreases the mechanical advantage of a machine |
| compound machine | contains two or more simple machines |
| efficiency of the machine | the ratio of work output to work input of a machine |
