| A | B |
|---|
| work | done when a force causes an object to move in the direction of the force |
| kinetic energy | the energy of movement |
| work (W) | Force x distance |
| joule (J) | unit used to measure energy |
| power | rate at which energy is done |
| watt | Joules/second; unit used to express power |
| machine | device that makes work easier by changing the size or direction of a force |
| work input | the work you do on a machine |
| input force | the force you apply to a machine |
| work output | work done by the machine on an object |
| output force | the force that is put out by the machine |
| mechanical advantage | number of times that a machine multiplies force |
| mechanical advantage (MA) | output force/input force |
| mechanical efficiency | comparison of s machine's work output with its work input; a percentage |
| lever | simple machine that consits of a bar that pivots on a fixed point |
| fulcrum | a fixed point on a simple machine |
| first-class lever | fulcrum found between the input force and the load |
| second-class lever | load is between the fulcrum and the input force |
| third-class lever | input force between the fulcrum and the load |
| pulley | a simple machine consisting of a wheel and rope |
| fixed pulley | pulley that is attached to something that does not move |
| moveable pulley | pulley that is attached to the object that moves |
| block and tackle pulley | a fied pulley and a moveable pulley that are used together |
| wheel and axle | a simple machine that made of two circular objects of different sizes |
| inclined plane | a simple machine that is a straight, slanted surface; a ramp |
| wedge | a pair of inclined planes that move; a knife |
| screw | an inclined plane wrapped around a cylinder |
| compound machine | a machine that is made of one or more simple machines; a can opener |
