| A | B |
|---|
| lever | a bar that pivots around a fixed point |
| mechanical advantage | the number of times that a machine multiplies the effort force |
| pulley | a wheel around which a rope or chain is passed |
| fulcrum | the fixed point around which a lever bar is free to move |
| machine | a device that makes work easier |
| inclined plane | a simple machine with a sloping surface |
| wheel & axle | a simple machine make up of 2 wheels that turn around the same point |
| compound machine | a machine made up of 2 or more simple machines |
| screw & wedge | inclined planes that move |
| formula for mechanical advantage | MA = length / height |
| 1st Class Lever (picture) |  |
| 2nd Class Lever (picture) |  |
| 3rd Class Lever (picture) |  |
| single movable pulley | doesn't change direction of force; cuts effort in half |
| single fixed pulley | changes direction of force; doesn't change effort |
| 1st Class Lever | lever that reduces effort & changes direction of force |
| 2nd Class Lever | lever that reduces force, but doesn't change its' direction |
| 3rd Class Lever | lever that doesn't reduce force or change its' direction |
| wheels that spin around an axle | reduce friction |
| when effort is applies to small wheel of wheel & axle | force is sacrificed |
| when effort is applied to large wheel of wheel & axle | distance & time are sacrificed |
