ASVAB Mechanical Comprehension Practice Test 76414 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.98
Score	0%	60%

Review

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

57% Answer Correctly

	air
	carbon
	water
	oil

Solution

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

The standard unit of energy is the:

73% Answer Correctly

	Joule
	Volt
	Horsepower
	Watt

Solution

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

Which of the following is the formula for gravitational potential energy?

61% Answer Correctly

	\(PE = mgh\)
	\(PE = { 1 \over 2} mv^2\)
	\(PE = { 1 \over 2} mg^2\)
	\(PE = mg^2h\)

Solution

Gravitational potential energy is energy by virtue of gravity. The higher an object is raised above a surface the greater the distance it must fall to reach that surface and the more velocity it will build as it falls. For gravitational potential energy, PE = mgh where m is mass (kilograms), h is height (meters), and g is acceleration due to gravity which is a constant (9.8 m/s²).

4 How much work can a 5 hp engine do in 10 seconds?

52% Answer Correctly

	0 ft⋅lb
	20 ft⋅lb
	27500 ft⋅lb
	2 ft⋅lb

Solution

Horsepower (hp) is a common measure of power output for complex machines. By definition, a 1 hp machine does 550 ft⋅lb of work in 1 second: 1 hp = 550 ft⋅lb/s. Substituting the variables for this problem gives us:
\( W = 5 hp \times 550 \frac{ft⋅lb}{s} \times 10s = 27500 ft⋅lb \)

Boyle's law defines the relationship between pressure and volume as:

57% Answer Correctly

	\({P_1}{P_2} = {V_1}{V_2}\)
	\(\frac{P_1}{P_2} = \frac{V_2}{V_1}\)
	\(\frac{P_1}{P_2} = {V_1}{V_2}\)
	\(\frac{P_1}{P_2} = \frac{V_1}{V_2}\)

Solution

Boyle's law states that "for a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional". Expressed as a formula, that's \(\frac{P_1}{P_2} = \frac{V_2}{V_1}\)