ASVAB Mechanical Comprehension Practice Test 974452 Results

Your Results Global Average
Questions 5 5
Correct 0 3.40
Score 0% 68%

Review

1

Friction resists movement in a direction __________ to the movement.

81% Answer Correctly

parallel

normal

perpendicular

opposite
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.

2

The standard unit of energy is the:

73% Answer Correctly

Horsepower

Volt

Joule

Watt
Solution

The Joule (J) is the standard unit of energy and has the unit \({kg \times m^2} \over s^2\).

3

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

56% Answer Correctly

power

efficiency

force multiplication

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.

4 If you lift a 38 lbs. rock 17 ft. from the ground, how much work have you done?
71% Answer Correctly
55 ft⋅lb
2 ft⋅lb
646 ft⋅lb
323 ft⋅lb
Solution
Work is force times distance. In this case, the force is the weight of the rock so:
\( W = F \times d \)
\( W = 38 \times 17 \)
\( W = 646 \)
5

Specific gravity is a comparison of the density of an object with the density of:

57% Answer Correctly

carbon

water

oil

air
Solution

Specific gravity is the ratio of the density of equal volumes of a substance and water and is measured by a hyrdometer.