| A | B |
|---|
| Force | A push or a pull. |
| Friction | A force that resists motion whenever one material rubs against another |
| Gravity | A force of attraction between all objects |
| Newton (N) | The SI unit for measuring force |
| Work | A measure of the transfer of energy to an object. Work, measured in joules, is equal to force, measured in newtons, times distance, measured in metres. |
| Joule (J) | The SI unit of work. A joule is the same as a newton metre |
| Mechanical advantage | The amount by which a machine can multiply a force |
| Machine | A device that helps people do work more easily |
| Load force | The force needed to move an object without using a machine |
| Effort force | The force needed to move an object when you are using a machine. |
| Simple machine | The six basic devices that make work easier and more convenient for us to do. They are the inclined plane, wedge, lever, pulley, and wheel-and-axle |
| Inclined plane | A simple machine that is a sloping surface along which a load is moved. |
| Wedge | A simple machine shaped like an incline plane. A wedge does work by being pushed into the object |
| Screw | A simple machine made up of an incline plane wrapped around a rod. A screw does work by moving into or through an object, such as a piece of wood |
| Lever | A simple machine made up of a bar this is supported at one point. Levers are sometimes used in pairs. For example, scissors are made of a pair of levers |
| Fulcrum | The support point in which a lever can rotate. |
| Pulley | A simple machine made from a rope or cable that is looped around a wheel. |
| Efficiency | The calculation of work done by a machine (the work output) as a percent of the work needed to operate it (the work output). |
