| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.06 |
| Score | 0% | 61% |
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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volume, mass |
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pressure, density |
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pressure, volume |
Boyle's law states that "for a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional".
Drag is a type of:
friction |
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kinetic energy |
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work |
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potential energy |
Drag is friction that opposes movement through a fluid like liquid or air. The amount of drag depends on the shape and speed of the object with slower objects experiencing less drag than faster objects and more aerodynamic objects experiencing less drag than those with a large leading surface area.
Normal force is generally equal to the __________ of an object.
density |
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mass |
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coefficient of friction |
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weight |
Normal force arises on a flat horizontal surface in response to an object's weight pressing it down. Consequently, normal force is generally equal to the object's weight.
Which class of lever offers no mechanical advantage?
third |
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second |
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first |
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none of these, all levers offer mechanical advantage |
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.
A fixed pulley is useful for which of the following?
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 |
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multiplying the input distance |
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.