ASVAB Mechanical Comprehension Practice Test 219356 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.80
Score	0%	56%

Review

According to Boyle's law, for a fixed amount of gas kept at a fixed temperature, which of the following are inversely proportional?

64% Answer Correctly

	pressure, volume
	volume, mass
	density, volume
	pressure, density

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".

The principle of moments defines equilibrium in terms of:

54% Answer Correctly

	torque
	power
	energy
	speed

Solution

According to the principle of moments, you can maintain equilibrium if the moments (forces) tending to clockwise rotation are equal to the moments tending to counterclockwise rotation. Another name for these moments of force is torque.

The mass of an object correlates to the size of the object but ultimately depends on:

67% Answer Correctly

	the object's density
	gravity
	the object's weight
	the object's potential energy

Solution

Mass is a measure of the amount of matter in an object. In general, larger objects have larger mass than smaller objects but mass ultimately depends on how compact (dense) a substance is.

4 What is the power output of a 2 hp engine that's 50% efficient?

40% Answer Correctly

	1100 \( \frac{ft⋅lb}{s} \)
	550 \( \frac{ft⋅lb}{s} \)
	1650 \( \frac{ft⋅lb}{s} \)
	0 \( \frac{ft⋅lb}{s} \)

Solution

\( Efficiency = \frac{Power_{out}}{Power_{in}} \times 100 \)
Solving for power out: \( P_{o} = \frac{E \times P_{i}}{100} \)
Knowing that 1 hp = 550 \( \frac{ft⋅lb}{s} \), P_i becomes 2 hp x 550 \( \frac{ft⋅lb}{s} \) = 1100 \( \frac{ft⋅lb}{s} \)
\( P_{o} = \frac{E \times P_{i}}{100} = \frac{50 \times 1100 \frac{ft⋅lb}{s}}{100} \) \( = \frac{55000 \frac{ft⋅lb}{s}}{100} \) = 550 \( \frac{ft⋅lb}{s} \)

Which of the following statements about this pulley configuration is false?

48% Answer Correctly

	Mechanical advantage is the number of ropes that support the resistance
	Changes the direction of and multiplies the effort force
	This is a block and tackle pulley configuration
	Only multiplies the effort force

Solution

A block and tackle is a combination of one or more fixed pulleys and one or more movable pulleys where the fixed pulleys change the direction of the effort force and the movable pulleys multiply it. The mechanical advantage is equal to the number of times the effort force changes direction and can be increased by adding more pulley wheels to the system. An easy way to find the mechanical advantage of a block and tackle pulley system is to count the number of ropes that support the resistance.