| A | B |
|---|
| machine | device that makes work easier |
| inclined plane | simple machine with a sloping surface |
| mechanical advantage (MA) | number of times a machine multiplies the effort force |
| screw | inclined plane that moves with a twist |
| wedge | movable inclined plane |
| MA for an inclined plane | length (of sloping surface) divided by height |
| lever | bar that pivots around a fixed point |
| fulcrum | fixed point around which the bar of a lever moves |
| first-class lever | changes the direction of the force and reduces effort force |
| second-class lever | reuces effort force but doesn' t change direction of force |
| third-class lever | doesn't reduce force or change its direction |
| pulley | wheel around which a rope or chain is passed |
| single fixed pulley | changes direction of the force, doesn't reduce effort force |
| single movable pulley | cuts effort force in half |
| wheel and axle | two wheels that pivot around the same point |
| compound machine | machine made of 2 or more simple machines |
| comfortable wheelchair ramp | length 10 times longer than height |
| gears | wheels with teeth that transfer force |
| effort applied to a large wheel | reduces effort force, but sacrifices speed |
| effort applied to a small wheel | gain speed, but sacrifice force |
| wheels that spin AROUND an axle | ONLY reduce friction |
| an advantage of a ramp | reduces effort force |
| disadvantage of a ramp | increases the distance |
