ASVAB Mechanical Comprehension Practice Test 94570 Results

Your Results Global Average
Questions 5 5
Correct 0 3.33
Score 0% 67%

Review

1 80 lbs. of effort is used by a machine to lift a 160 lbs. box. What is the mechanical advantage of the machine?
84% Answer Correctly
6
1.8
2.2
2
Solution

Mechanical advantage is resistance force divided by effort force:

MA = \( \frac{F_r}{F_e} \) = \( \frac{160 lbs.}{80 lbs.} \) = 2

2

Which of the following surfaces would have the highest coefficient of friction?

77% Answer Correctly

concrete

marble

steel

ice
Solution

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.

3 If the radius of the axle is 7 and the radius of the wheel is 10, what is the mechanical advantage of this wheel and axle configuration?
52% Answer Correctly
10
3
1.43
7
Solution

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 10 and the output radius (where the resistance is being applied) is 7 for a mechanical advantage of \( \frac{10}{7} \) = 1.43

4

Coplanar forces:

61% Answer Correctly

act along the same line of action

have opposite dimensions

act in a common plane

pass through a common point
Solution

Collinear forces act along the same line of action, concurrent forces pass through a common point and coplanar forces act in a common plane.

5

Which of the following will increase the mechanical advantage of this inclined plane?

58% Answer Correctly

lower the force acting at the blue arrow

increase the force acting at the blue arrow

lengthen the ramp

shorten the ramp
Solution

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.