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Chapter 5 Vocab
| Term | Definition |
|---|---|
| energy | the ability to cause change |
| work | transfer of energy that occurs when a force makes an object move; measured in joules |
| power | amount of work done, or the amount of energy transferred, divided by the time required to do the work or transfer the energy; measured in watts |
| force | a push or pull |
| machine | device that makes doing work easier by increasing the force applied to an object, changing the direction of an applied force, or increasing the distance over which a force can be applied. |
| input force | the force that is applied to the machine or object |
| output force | the force applied by the machine or object |
| mechanical advantage | ratio of the output force exerted by a machine to the input force applied to the machine |
| efficiency | ratio of the output work done by the machine to the input work done on the machine; expressed by percentage |
| compound | composed of separate elements or parts |
| simple machine | machine that does work with only one movement-lever,pulley,wheel and axle,inclined plane,screw,and wedge |
| lever | simple machine consisting of a bar free to pivot about a fixed point called the fulcrum |
| pulley | simple machine that consists of a grooved wheel with a rope, chain, or cable running along the groove, can be either fixed or moveable |
| wheel and axle | simple machine that consists of a shaft or axle attached to the center of a larger wheel,so that the shaft and the wheel rotate together. |
| inclined plane | simple machine that consists of a sloping surface, such as a ramp, that reduces the amount of force needed to lift something by increasing the distance over which the force is applied. |
| screw | simple machine that consists of an inclined plane wrapped in a spiral around a cylindrical post. |
| wedge | simple machine that is an inclined plane with one or two sloping sides. |
| compound machine | machine that is a combination of two or more simple machines. |