ASVAB Mechanical Comprehension Practice Test 151416 Results

Your Results Global Average
Questions 5 5
Correct 0 3.24
Score 0% 65%

Review

1 10 lbs. of effort is used by a machine to lift a 80 lbs. box. What is the mechanical advantage of the machine?
84% Answer Correctly
8
12
24
10
Solution

Mechanical advantage is resistance force divided by effort force:

MA = \( \frac{F_r}{F_e} \) = \( \frac{80 lbs.}{10 lbs.} \) = 8

2

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

49% Answer Correctly

wind load

live 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.

3 If the handles of a wheelbarrow are 0.5 ft. from the wheel axle, how many pounds of force must you exert to lift the handles if it's carrying a 170 lbs. load concentrated at a point 0.5 ft. from the axle?
52% Answer Correctly
4.4
313.5
514.2
170
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 effort force:
\( F_e = \frac{F_r d_r}{d_e} \)
\( F_e = \frac{170 \times 0.5}{0.5} \)
\( F_e = \frac{85.0}{0.5} \)
\( F_e = 170 \)
4

The steering wheel of a car is an example of which type of simple machine?

89% Answer Correctly

wheel and axle

fixed pulley

first-class lever

block and tackle
Solution

A wheel and axle uses two different diameter wheels mounted to a connecting axle. Force is applied to the larger wheel and large movements of this wheel result in small movements in the smaller wheel. Because a larger movement distance is being translated to a smaller distance, force is increased with a mechanical advantage equal to the ratio of the diameters of the wheels. An example of a wheel and axle is the steering wheel of a car.

5

A truck is using a rope to pull a car. Tension in the rope is greatest in which of the following places?

50% Answer Correctly

tension is equal in all parts of the rope

near the truck

in the middle

near the car
Solution

Tension is a force that stretches or elongates something. When a cable or rope is used to pull an object, for example, it stretches internally as it accepts the weight that it's moving. Although tension is often treated as applying equally to all parts of a material, it's greater at the places where the material is under the most stress.