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work machines
Work and Simple Machines
Question | Answer |
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Work | is done when a force exerted on an object causes that object to move some distance; equal to force times distance; measured in joules. |
Power | rate at which work is done; equal to the work done divided by the time it takes to do the work; measured in watts. |
Input Force | force exerted on a machine |
Output Force | force exerted by a machine |
Mechanical advantage | number of times the input force is multiplied by a machine; equal to the output force divided by the input force |
efficiency | equals the output work divided by the input work; expressed as a percentage |
simple machine | a machine that does work with only one movement; includes the inclined plane, wedge, screw, lever, wheel and axle, and pulley. |
compound machine | machine made up of a combination of two or more simple machines |
inclined plane | simple machine that is a flat surface, sloped surface, or ramp |
wedge | simple machine consisting of an inclined plane that moves; can have one or two sloping sides |
screw | simple machine that is an inclined plane wrapped around a cylinder or post |
lever | simple machine consisting of a rigid rod or plank that pivots or rotates around a fixed point called the fulcrum |
wheel and axle | simple machine made from two circular objects of different sizes that are attached and rotate together |
pulley | simple machine made from a grooved wheel with a rope or cable wrapped around the groove |