ASVAB Mechanical Comprehension Practice Test 364475 Results

Your Results Global Average
Questions 5 5
Correct 0 3.05
Score 0% 61%

Review

1 If input effort is 400 ft⋅lb, what output effort will be produced by a machine with a mechanical advantage of 5?
79% Answer Correctly
500ft⋅lb
4000ft⋅lb
1000ft⋅lb
2000 ft⋅lb
Solution
Mechanical advantage is the ratio of output force to input force and tells us by how many times a machine multiplies input effort. So, a machine with a mechanical advantage of 5 will multiply an input effort of 400 ft⋅lb by 5 to produce an output effort of 2000 ft⋅lb.
2

Depending on where you apply effort and resistance, the wheel and axle can multiply:

45% Answer Correctly

force or distance

force or speed

speed or power

power or distance
Solution

If you apply the resistance to the axle and the effort to the wheel, the wheel and axle will multiply force and if you apply the resistance to the wheel and the effort to the axle, it will multiply speed.

3

Which of the following is not a type of structural load?

49% Answer Correctly

dead load

live load

wind load

occupancy load
Solution

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.

4

A ramp is an example of which kind of simple machine?

84% Answer Correctly

wedge

first-class lever

none of these

inclined plane
Solution

An inclined plane is a simple machine that reduces the force needed to raise an object to a certain height. Work equals force x distance and, by increasing the distance that the object travels, an inclined plane reduces the force necessary to raise it to a particular height. In this case, the mechanical advantage is to make the task easier. An example of an inclined plane is a ramp.

5 If the handles of a wheelbarrow are 1.5 ft. from the wheel axle and the load is concentrated at a point 1.0 ft. from the axle, how many pounds of load will a 210 lbs. force lift?
47% Answer Correctly
161.2
315
0
83
Solution
This problem describes a second-class lever and, for a second class lever, the effort force multiplied by the effort distance equals the resistance force multipied by the resistance distance: Fede = Frdr. In this problem we're looking for resistance force:
\( F_r = \frac{F_e d_e}{d_r} \)
\( F_r = \frac{210 \times 1.5}{1.0} \)
\( F_r = \frac{315.0}{1.0} \)
\( F_r = 315 \)