ASVAB Mechanical Comprehension Practice Test 265404 Results

Your Results Global Average
Questions 5 5
Correct 0 3.56
Score 0% 71%

Review

1

A wedge is most similar to what other type of simple machine?

70% Answer Correctly

first-class lever

second-class lever

inclined plane

third-class lever


Solution

The wedge is a moving inclined plane that is used to lift, hold, or break apart an object. A wedge converts force applied to its blunt end into force perpendicular to its inclined surface. In contrast to a stationary plane where force is applied to the object being moved, with a wedge the object is stationary and the force is being applied to the plane. Examples of a wedge include knives and chisels.


2 If you have a gear train with two gears, the first with 32 teeth and the second with 8 teeth, how many revolutions does the second gear make for each revolution of the first gear?
77% Answer Correctly
8
12
6
4

Solution

The gear ratio (Vr) of a gear train 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 only two gears so the equation becomes:

Vr = \( \frac{N_1}{N_2} \) = \( \frac{32}{8} \) = 4


3

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

80% Answer Correctly

 kinetic energy

heat

power

work


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.


4

For a hydraulic system, pressure applied to the input of the system will increase the pressure in which parts of the system?

58% Answer Correctly

all of these are correct

the portions of the system at an altitude above the input

everywhere in the system

the portions of the system at an altitude below the input


Solution

Pascal's law states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere. For a hydraulic system, this means that a pressure applied to the input of the system will increase the pressure everywhere in the system.


5

A watt is the unit for which of the following?

71% Answer Correctly

power

mechanical advantage

energy

work


Solution

Power is the rate at which work is done, P = w/t, or work per unit time. The watt (W) is the unit for power and is equal to 1 joule (or newton-meter) per second. Horsepower (hp) is another familiar unit of power used primarily for rating internal combustion engines. 1 hp equals 746 watts.