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PS Ch 5 Vocab LD
Sections 1, 2, + 3
| Question | Answer |
|---|---|
| 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. |
| 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. |
| output force | The force applied by the machine. |
| 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 as a percentage. |
| 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 pint called the fulcrum. |
| pulley | simple machine that consists of a grooved wheel with a rope, chain, or cable running alone the groove; can be either fixed or movable. |
| 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. |
| wedge | simple machine that is an inclined plane wit one or two sloping slides. |
| compound machine | machine that is a combination of two or more simple machines. |