ASVAB Mechanical Comprehension Practice Test 290298 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.13
Score	0%	63%

Review

Which of the following is not a type of bridge?

74% Answer Correctly

	arch
	cable
	block
	truss

Solution

The six basic bridge forms are beam, truss, arch, cantilever, cable, and suspension.

2 If you lift a 27 lbs. rock 30 ft. from the ground, how much work have you done?

70% Answer Correctly

	1 ft⋅lb
	810 ft⋅lb
	1620 ft⋅lb
	-3 ft⋅lb

Solution

Work is force times distance. In this case, the force is the weight of the rock so:
\( W = F \times d \)
\( W = 27 \times 30 \)
\( W = 810 \)

Which of these is the formula for kinetic energy?

67% Answer Correctly

	\(KE = {m \over v^2 }\)
	\(KE = {1 \over 2}mh^2\)
	\(KE = mgh\)
	\(KE = {1 \over 2}mv^2\)

Solution

Kinetic energy is the energy of movement and is a function of the mass of an object and its speed: \(KE = {1 \over 2}mv^2\) where m is mass in kilograms, v is speed in meters per second, and KE is in joules. The most impactful quantity to kinetic energy is velocity as an increase in mass increases KE linearly while an increase in speed increases KE exponentially.

Which of these will have the most impact on the kinetic energy of an object?

54% Answer Correctly

	its weight
	its direction
	its mass
	its speed

Solution

5 If the handles of a wheelbarrow are 2.5 ft. from the wheel axle and the load is concentrated at a point 0.5 ft. from the axle, how many pounds of load will a 130 lbs. force lift?

47% Answer Correctly

	650
	26
	104
	88

Solution

This problem describes a second-class lever and, for a second class lever, the effort force multiplied by the effort distance equals the resistance force multipied by the resistance distance: F_ed_e = F_rd_r. In this problem we're looking for resistance force:
\( F_r = \frac{F_e d_e}{d_r} \)
\( F_r = \frac{130 \times 2.5}{0.5} \)
\( F_r = \frac{325.0}{0.5} \)
\( F_r = 650 \)