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1 Ch - Phy Sc M 8B
Physics - Energy (Apologia Physical Science M 8B)
Question | Answer |
---|---|
work | the product of a force (applied in the direction of motion of an object) and the distance the object moves |
power | the amount of work done each second |
input force | the force a person exerts on a machine |
output force | the force exerted by a machine |
input distance | the distance the input force is applied |
output distance | the distance the output force is exerted through, or how far the load moves |
actual mechanical advantage (AMA) | ratio of the output FORCE to the input FORCE (output force/input force) |
ideal mechanical advantage (IMA) | a measure of a machine's mechanical advantage in the absence of friction (input DISTANCE/output DISTANCE) |
efficiency | the percentage of work input that becomes work output |
Efficiency = | work output/work input X 100% |
compound machines | machines made up of two or more simple machines that operate together |
work = | force X distance |
power = | Work divided by time |
SI unit of power | watt (W), which = 1 joule per second (J/s) |
James Watt | 1736-1819, coined the term horsepower when working to improve the efficiency of his steam engine; SI unit for power is named for him |
A machine either changes | the size of a force, the direction of the force, or the distance over which a force is applied. |
six types of simple machines | inclined plane, edge, screw, lever, wheel and axle, pulley |