| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.31 |
| Score | 0% | 66% |
The science that deals with motion and the forces that produce motion is called which of the following?
engineering |
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aeronautics |
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mechanics |
|
physics |
Mechanics deals with motion and the forces that produce motion.
| 8 | |
| 16 | |
| 7 | |
| 12 |
The mechanical advantage (MA) of a wedge is its length divided by its thickness:
MA = \( \frac{l}{t} \) = \( \frac{32 in.}{4 in.} \) = 8
Friction between two or more solid objects that are not moving relative to each other is called:
gravitational friction |
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dynamic friction |
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kinetic friction |
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static friction |
Static friction is friction between two or more solid objects that are not moving relative to each other. An example is the friction that prevents a box on a sloped surface from sliding farther down the surface.
The mechanical advantage of a block and tackle is equal to which of the following?
the number of input forces |
|
the number of pulleys |
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the number of connecting ropes |
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the number of loads |
Two or more pulleys used together constitute a block and tackle which, unlike a fixed pulley, does impart mechanical advantage as a function of the number of pulleys that make up the arrangement. So, for example, a block and tackle with three pulleys would have a mechanical advantage of three.
| 5 | |
| 1.6 | |
| 8 | |
| 0.63 |
The mechanical advantage of a wheel and axle is the input radius divided by the output radius:
MA = \( \frac{r_i}{r_o} \)
In this case, the input radius (where the effort force is being applied) is 8 and the output radius (where the resistance is being applied) is 5 for a mechanical advantage of \( \frac{8}{5} \) = 1.6