ASVAB Mechanical Comprehension Practice Test 524273 Results

Your Results Global Average
Questions 5 5
Correct 0 2.94
Score 0% 59%

Review

1 A 460 lb. barrel is rolled up a 15 ft. ramp to a platform that's 3 ft. tall. What effort is required to move the barrel?
53% Answer Correctly
46 lbs.
92 lbs.
82.8 lbs.
138 lbs.
Solution

This problem describes an inclined plane and, for an inclined plane, the effort force multiplied by the effort distance equals the resistance force multipied by the resistance distance:

Fede = Frdr

Plugging in the variables from this problem yields:

Fe x 15 ft. = 460 lbs. x 3 ft.
Fe = \( \frac{1380 ft⋅lb}{15 ft.} \) = 92 lbs.

2

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

50% Answer Correctly

dead load

wind load

occupancy load

live 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.

3 A mass of air has a pressure of 12.0 psi and a volume of 60 ft.3. If the air is compressed to a new volume of 35 ft.3, what is the new pressure?
56% Answer Correctly
11.6 psi
20.6 psi
30.9 psi
41.1 psi
Solution

According to Boyle's Law, pressure and volume are inversely proportional:

\( \frac{P_1}{P_2} \) = \( \frac{V_2}{V_1} \)

In this problem, V2 = 35 ft.3, V1 = 60 ft.3 and P1 = 12.0 psi. Solving for P2:

P2 = \( \frac{P_1}{\frac{V_2}{V_1}} \) = \( \frac{12.0 psi}{\frac{35 ft.^3}{60 ft.^3}} \) = 20.6 psi

4 If A = 7 ft. and the green box weighs 45 lbs. what is the torque acting on the A side of this lever?
74% Answer Correctly
945 ft⋅lb
315 ft⋅lb
105 ft⋅lb
157 ft⋅lb
Solution
For a lever, torque is weight x distance from the fulcrum which, in this case, is: 45 ft. x 7 lbs. = 315 ft⋅lb
5

Which of the following is the formula for torque?

61% Answer Correctly

τ = rF

τ = r/F

τ = F/r2

τ = F/r
Solution

Torque measures force applied during rotation: τ = rF.  Torque (τ, the Greek letter tau) = the radius of the lever arm (r) multiplied by the force (F) applied. Radius is measured from the center of rotation or fulcrum to the point at which the perpendicular force is being applied. The resulting unit for torque is newton-meter (N-m) or foot-pound (ft-lb).