ASVAB Mechanical Comprehension Practice Test 19809 Results

Your Results Global Average
Questions 5 5
Correct 0 3.18
Score 0% 64%

Review

1

The principle of conservation of mechanical energy states that, as long as no other forces are applied, what will remain constant as an object falls?

45% Answer Correctly

total mechanical energy

kinetic energy

acceleration

potential energy
Solution

As an object falls, its potential energy is converted into kinetic energy. The principle of conservation of mechanical energy states that, as long as no other forces are applied, total mechanical energy (PE + KE) of the object will remain constant at all points in its descent.

2 If the radius of the axle is 7 and the radius of the wheel is 10, what is the mechanical advantage of this wheel and axle configuration?
52% Answer Correctly
3
10
7
1.43
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 10 and the output radius (where the resistance is being applied) is 7 for a mechanical advantage of \( \frac{10}{7} \) = 1.43

3 If input effort is 400 ft⋅lb, what output effort will be produced by a machine with a mechanical advantage of 5?
79% Answer Correctly
500ft⋅lb
2000 ft⋅lb
0ft⋅lb
8000ft⋅lb
Solution
Mechanical advantage is the ratio of output force to input force and tells us by how many times a machine multiplies input effort. So, a machine with a mechanical advantage of 5 will multiply an input effort of 400 ft⋅lb by 5 to produce an output effort of 2000 ft⋅lb.
4

Friction resists movement in a direction __________ to the movement.

81% Answer Correctly

parallel

opposite

perpendicular

normal
Solution

Friction resists movement. Kinetic (also called sliding or dynamic) friction resists movement in a direction opposite to the movement. Because it opposes movement, kinetic friction will eventually bring an object to a stop. An example is a rock that's sliding across ice.

5

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

61% Answer Correctly

chemically stable

low corrosive action

high melting point

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.