| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.87 |
| Score | 0% | 57% |
A fixed pulley is useful for which of the following?
changing the direction of the output force |
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multiplying the input force |
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multiplying the input distance |
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changing the direction of the input force |
A fixed pulley is used to change the direction of a force and does not multiply the force applied. As such, it has a mechanical advantage of one. The benefit of a fixed pulley is that it can allow the force to be applied at a more convenient angle, for example, pulling downward or horizontally to lift an object instead of upward.
According to Boyle's law, for a fixed amount of gas kept at a fixed temperature, which of the following are inversely proportional?
density, volume |
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pressure, density |
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pressure, volume |
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volume, mass |
Boyle's law states that "for a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional".
Which of the following surfaces would have the lowest coefficient of friction?
ice |
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leather |
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tile |
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concrete |
Coefficient of friction (μ) represents how much two materials resist sliding across each other. Smooth surfaces like ice have low coefficients of friction while rough surfaces like concrete have high μ.
What's the last gear in a gear train called?
driver gear |
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driven gear |
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idler gear |
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output gear |
A gear train is two or more gears linked together. Gear trains are designed to increase or reduce the speed or torque outpout of a rotating system or change the direction of its output. The first gear in the chain is called the driver and the last gear in the chain the driven gear with the gears between them called idler gears.
| 199.6 | |
| -20 | |
| 0 | |
| 480 |