ASVAB Mechanical Comprehension Practice Test 983580 Results

Your Results Global Average
Questions 5 5
Correct 0 2.90
Score 0% 58%

Review

1

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

in the middle

near the truck

tension is equal in all parts of the rope

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.


2

Potential energy is energy that has the potential to be converted into what?

81% Answer Correctly

work

power

heat

 kinetic energy


Solution

Potential energy is the energy of an object by virtue of its position relative to other objects. It is energy that has the potential to be converted into kinetic energy.


3 If you have a gear train with three gears, the first with 24 teeth, the second with 14 teeth, and the third with 4 teeth, what is its mechanical advantage?
51% Answer Correctly
7
3
9
6

Solution

The mechanical advantage of a gear train is its gear ratio. The gear ratio (Vr) is the product of the gear ratios between the pairs of meshed gears. Let N represent the number of teeth for each gear:

Vr = \( \frac{N_1}{N_2} \) \( \frac{N_2}{N_3} \) \( \frac{N_3}{N_4} \) ... \( \frac{N_n}{N_{n+1}} \)

In this problem, we have three gears so the equation becomes:

Vr = \( \frac{N_1}{N_2} \) \( \frac{N_2}{N_3} \) = \( \frac{24}{14} \) \( \frac{14}{4} \) = \( \frac{24}{4} \) = 6


4

What type of load creates different stresses at different locations on a structure?

61% Answer Correctly

impact load

non-uniformly distributed load

static uniformly distributed load

dynamic load


Solution

A concentrated load acts on a relatively small area of a structure, a static uniformly distributed load doesn't create specific stress points or vary with time, a dynamic load varies with time or affects a structure that experiences a high degree of movement, an impact load is sudden and for a relatively short duration and a non-uniformly distributed load creates different stresses at different locations on a structure.


5 If the handles of a wheelbarrow are 2.5 ft. from the wheel axle and the load is concentrated at a point 1.5 ft. from the axle, how many pounds of load will a 230 lbs. force lift?
47% Answer Correctly
383.3
0
345
49

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:
\( F_r = \frac{F_e d_e}{d_r} \)
\( F_r = \frac{230 \times 2.5}{1.5} \)
\( F_r = \frac{575.0}{1.5} \)
\( F_r = 383.3 \)