| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.98 |
| Score | 0% | 60% |
| 1 | |
| -1 | |
| 1 | |
| 8 |
The mechanical advantage of a wheel and axle lies in the difference in radius between the inner (axle) wheel and the outer wheel. But, this mechanical advantage is only realized when the input effort and load are applied to different wheels. Applying both input effort and load to the same wheel results in a mechanical advantage of 1.
Normal force is generally equal to the __________ of an object.
weight |
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density |
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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.
A fixed pulley has a mechanical advantage of:
0 |
|
-1 |
|
2 |
|
1 |
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.
Which of the following is not a type of structural load?
wind load |
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live load |
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dead load |
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occupancy load |
Dead load is the weight of the building and materials, live load is additional weight due to occupancy or use, snow load is the weight of accumulated snow on a structure and wind load is the force of wind pressures against structure surfaces.
| 3 | |
| 9 | |
| 2.7 | |
| 3.3 |
Mechanical advantage is resistance force divided by effort force:
MA = \( \frac{F_r}{F_e} \) = \( \frac{180 lbs.}{60 lbs.} \) = 3