| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.00 |
| Score | 0% | 60% |
Which of the following represents how much two materials resist sliding across each other?
coefficient of friction |
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normal friction |
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static friction |
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kinetic friction |
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.
Which of the following will increase the mechanical advantage of this inclined plane?
lengthen the ramp |
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lower the force acting at the blue arrow |
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increase the force acting at the blue arrow |
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shorten the ramp |
The mechanical advantage (MA) of an inclined plane is the effort distance divided by the resistance distance. In order to increase mechanical advantage, this ratio must increase which means making the effort distance longer and this can be accomplished by lengthening the length of the ramp.
A wedge is most similar to what other type of simple machine?
first-class lever |
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inclined plane |
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second-class lever |
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third-class lever |
The wedge is a moving inclined plane that is used to lift, hold, or break apart an object. A wedge converts force applied to its blunt end into force perpendicular to its inclined surface. In contrast to a stationary plane where force is applied to the object being moved, with a wedge the object is stationary and the force is being applied to the plane. Examples of a wedge include knives and chisels.
Normal force is generally equal to the __________ of an object.
density |
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weight |
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mass |
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coefficient of friction |
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.
For a hydraulic system, pressure applied to the input of the system will increase the pressure in which parts of the system?
the portions of the system at an altitude above the input |
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everywhere in the system |
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all of these are correct |
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the portions of the system at an altitude below the input |
Pascal's law states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere. For a hydraulic system, this means that a pressure applied to the input of the system will increase the pressure everywhere in the system.