| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.53 |
| Score | 0% | 71% |
An object's resistance to changes in direction is known as:
inertia |
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kinetic energy |
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weight |
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mass |
The more mass a substance has the more force is required to move it or to change its direction. This resistance to changes in direction is known as inertia.
A block and tackle with four pulleys would have a mechanical advantage of:
1 |
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2 |
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4 |
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0 |
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.
| 440 ft. | |
| 220 ft. | |
| 2 ft. | |
| 55 ft. |
Win = Wout
Feffort x deffort = Fresistance x dresistance
In this problem, the effort work is 220 ft⋅lb and the resistance force is 110 lbs. and we need to calculate the resistance distance:
Win = Fresistance x dresistance
220 ft⋅lb = 110 lbs. x dresistance
dresistance = \( \frac{220ft⋅lb}{110 lbs.} \) = 2 ft.
Which of the following will increase the mechanical advantage of this inclined plane?
lengthen the ramp |
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increase the force acting at the blue arrow |
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shorten the ramp |
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lower the force acting at the blue arrow |
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.
Which of the following is not a type of simple machine?
screw |
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lever |
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pulley |
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gear |
The six types of simple machines are the lever, wheel and axle, pulley, inclined plane, wedge, and screw.