| A | B |
|---|
| work | result of a force moves an object over a distance |
| joule | unit used to measure work |
| simple machine | machine with few or no moving parts that makes it easier to do work |
| inclined plane | flat surface with one end higher than the other |
| screw | inclined plane wrapped around a rod |
| wedge | inclined plane with one or two sloping sides |
| lever | rigid bar that turns around a fixed point |
| first class lever | fulcrum in middle |
| second class lever | resistance in middle |
| third class lever | effort in middle |
| wheel and axle | large wheel fixed to a smaller wheel or shaft called the axle |
| pulley | kind of wheel with a groove for a rope or cable |
| compound machine | two or more simple machines used together |
| efficiency | amount of work a machine does compared to the amount of energy put into using the machine |
| effort | force applied to do work |
| force | push or a pull |
| energy | ability to do work |
| friction | force caused by one object rubbing against another |
| fulcrum | point around which a lever pivots |
| newton | unit used to measure force |
| potential energy | stored energy |
| kinetic energy | energy of motion |
| resistance | force exerted by something you are trying to move |
