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Related Flashcards
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Cards In This Set
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Work
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Is done when a force that is applied to an object moves that object.
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Work Formula
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Is calculated by multiplying the force by the amount of movement of an object (W = F * d). Force is measured in N (newtons) and distance in m (meters).
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 Vocabulary Note (Work) - 1 |
If a force is to do WORK on an object, it must act in the same direction as the object moves. If there is NO movement, then NO WORK is done.
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Joule
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Is equal to the energy used to accelerate a body with a mass of one kilogram using one newton of force over a distance of one meter. One joule is also equivalent to one watt-second.
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Power
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Is the rate of doing work. It is the amount of energy consumed per unit time. Having no direction, it is a scalar quantity.
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Unit of Power
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Is the joule per second (J/s), known as the watt in honor of James Watt, the eighteenth-century developer of the steam engine.
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 Vocabulary Note (Power) - 2 |
If you do work at a faster rate, requires more power. You increase POWER, you can increase the amount of WORK done in a given TIME.
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Power Formula
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Power P = work / time (W ⁄ t). Energy E is in joules, and time t is in seconds. 1 W = 1 J/s. W = F * d)
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Watt (W) -
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Is an SI unit of power, which is equal to 1J/s. So 50 J/s = 50W.
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 Horsepower (hp) - |
Is 550 foot-pounds per second is approximately equivalent to 745.7 watts. This unit was first defined by James Watt (1736-1819).
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 Vocabulary Note (Machines) - 3 |
Machines make work easier to perform. They change the size of a force needed, the direction of a force, or the distance over which a force acts.
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 Simple Machine |
Is a mechanical device that changes the direction or magnitude of a force.
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Input (effort) Force -
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Effort force is the force applied to a machine or input force is the work done on a machine.
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Work Input -
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Is the work input of a machine is equal to the effort force times the distance over which the effort force is exerted.
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Input Distance -
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Is the distance the input force acts through.
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