| A | B |
|---|
| work | transfer of energy through motion |
| power | rate at which work is done |
| joule | standard SI unit for work |
| simple machine | any device that makes work easier and is done in only one movement |
| effort force | force applied to a simple machine |
| resistance force | force applied by the simple machine |
| input force | another name for effort force |
| output force | another name for resistance force |
| efficiency | measure of how much of the work put into a machine is changed into useful work |
| ideal machine | fictional machine in which no friction or gravity affects occur |
| lever | bar that is free to pivot about a fixed point |
| fulcrum | part of lever about which it pivots |
| effort arm | part of lever to which effort force is applied; distance is from force over to fulcrum |
| resistance arm | part of lever that exerts force on another object; distance is from where force is applied over to fulcrum |
| first class lever | fulcrum lies somewhere between the effort and resistance; purpose is to multiply distance or force |
| second class lever | resistance lies between fulcrum and effort; purpose is to multiply force |
| third class lever | effort lies between fulcrum and resistance; purpose is to increase range and speed of motion |
| mechanical advantage | the number of times that a machine multiples the effort force |
| inclined plane | sloping surface used to raise objects |
| wedge | inclined plane with 1 or 2 sloping sides that moves through the material |
| screw | inclined plane wrapped in a spiral around a post |
| complex, or compound machine | combination of 2 or more simple machines |
| pulley | grooved wheel with a rope or chain running along the groove |
| fixed pulley | attached to something that does not move; IMA = 1 |
| moveable pulley | attached to something that can move; IMA = 2 |
| block and tackle | combination of fixed and moveable pulleys; IMA = # of supporting ropes |
| wheel and axle | two wheels of different sizes that rotate together |
