ASVAB Mechanical Comprehension Practice Test 843369 Results

Your Results Global Average
Questions 5 5
Correct 0 3.09
Score 0% 62%

Review

1 What's the mechanical advantage of a wedge that's 2 inches wide and 6 inches long?
83% Answer Correctly
12
3
9
3.3

Solution

The mechanical advantage (MA) of a wedge is its length divided by its thickness:

MA = \( \frac{l}{t} \) = \( \frac{6 in.}{2 in.} \) = 3


2

The measure of how much of the power put into a machine is turned into movement or force is called:

56% Answer Correctly

power

force multiplication

efficiency

mechanical advantage


Solution

The efficiency of a machine describes how much of the power put into the machine is turned into movement or force. A 100% efficient machine would turn all of the input power into output movement or force. However, no machine is 100% efficient due to friction, heat, wear and other imperfections that consume input power without delivering any output.


3 The radius of the axle is 5, the radius of the wheel is 6, and the blue box weighs 85 lbs. What is the effort force necessary to balance the load?
53% Answer Correctly
5 lbs.
30 lbs.
6 lbs.
70.83 lbs.

Solution

The mechanical advantage of a wheel and axle is the input radius divided by the output radius:

MA = \( \frac{r_i}{r_o} \)

In this case, the input radius (where the effort force is being applied) is 6 and the output radius (where the resistance is being applied) is 5 for a mechanical advantage of \( \frac{6}{5} \) = 1.2

MA = \( \frac{load}{effort} \) so effort = \( \frac{load}{MA} \) = \( \frac{85 lbs.}{1.2} \) = 70.83 lbs.


4

Which of the following is not a characteristic of a ceramic?

60% Answer Correctly

chemically stable

high melting point

low corrosive action

low density


Solution

Ceramics are mixtures of metallic and nonmetallic elements that withstand exteme thermal, chemical, and pressure environments. They have a high melting point, low corrosive action, and are chemically stable. Examples include rock, sand, clay, glass, brick, and porcelain.


5

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

the portions of the system at an altitude below the input

the portions of the system at an altitude above the input

all of these are correct

everywhere in the system


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.