ASVAB Mechanical Comprehension Practice Test 625327 Results

Your Results Global Average
Questions 5 5
Correct 0 3.02
Score 0% 60%

Review

1 If A = 7 ft. and the green box weighs 15 lbs. what is the torque acting on the A side of this lever?
75% Answer Correctly
52 ft⋅lb
210 ft⋅lb
315 ft⋅lb
105 ft⋅lb
Solution
For a lever, torque is weight x distance from the fulcrum which, in this case, is: 15 ft. x 7 lbs. = 105 ft⋅lb
2 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?
36% Answer Correctly
1
1
3
-3
Solution

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.

3

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

49% Answer Correctly

live load

wind load

dead 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

The force exerted on an object due to gravity is called:

70% Answer Correctly

mass

density

weight

potential energy
Solution

Mass is an intrinsic property of matter and does not vary. Weight is the force exerted on the mass of an object due to gravity and a specific case of Newton's Second Law of Motion. Replace force with weight and acceleration with acceleration due to gravity on Earth (g) and the result is the formula for weight: W = mg or, substituting for g, weight equals mass multiplied by 9.8 m/s2.

5 What is the efficiency of a machine has work input of 85 ft⋅lb and work output of 29 ft⋅lb?
67% Answer Correctly
35%
2%
8%
70%
Solution
Due to friction, a machine will never be able to utilize 100% of its work input. A certain percentage of that input will be lost in overcoming friction within the machine. Effeciency is a measure of how much of a machine's work input can be turned into useful work output and is calculated by dividing work output by work input and multiplying the result by 100:
\( Efficiency = \frac{Work_{out}}{Work_{in}} \times 100 \) \( = \frac{29 ft⋅lb}{85 ft⋅lb} \times 100 \) \( = 35% \) %