| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.66 |
| Score | 0% | 53% |
A fixed pulley is useful for which of the following?
multiplying the input distance |
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multiplying the input force |
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changing the direction of the input force |
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changing the direction of the output 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.
Boyle's law defines the relationship between pressure and volume as:
\(\frac{P_1}{P_2} = \frac{V_1}{V_2}\) |
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\({P_1}{P_2} = {V_1}{V_2}\) |
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\(\frac{P_1}{P_2} = {V_1}{V_2}\) |
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\(\frac{P_1}{P_2} = \frac{V_2}{V_1}\) |
Boyle's law states that "for a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional". Expressed as a formula, that's \(\frac{P_1}{P_2} = \frac{V_2}{V_1}\)
Sam can do 50 ft. lb. of work in 2 minutes and 5 seconds. What would Sam have to do to increase his power output?
do 25 ft. lb. of work in 2 minutes 5 seconds |
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do the work in 3 minutes |
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do 100 ft. lb. of work in 4 minutes 12 seconds |
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do the work in 2 minutes |
Power is the rate of doing work or \(\frac{W}{t}\). To increase power, increase the work being done in the same amount of time or do the same amount of work in less time.
The advantage of using a third-class lever is that it increases:
the force applied to the load |
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the distance traveled by the load |
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the mechanical advantage of the lever |
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the speed of the load |
A third-class lever is used to increase distance traveled by an object in the same direction as the force applied. The fulcrum is at one end of the lever, the object at the other, and the force is applied between them. This lever does not impart a mechanical advantage as the effort force must be greater than the load but does impart extra speed to the load. Examples of third-class levers are shovels and tweezers.
| 130 | |
| -26.8 | |
| 260 | |
| None of these is correct |