ASVAB Mechanical Comprehension Practice Test 450601 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.81
Score	0%	56%

Review

1 If the handles of a wheelbarrow are 0.5 ft. from the wheel axle and the load is concentrated at a point 1.5 ft. from the axle, how many pounds of load will a 160 lbs. force lift?

47% Answer Correctly

	-59
	213.3
	240
	53.3

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:
\( F_r = \frac{F_e d_e}{d_r} \)
\( F_r = \frac{160 \times 0.5}{1.5} \)
\( F_r = \frac{80.0}{1.5} \)
\( F_r = 53.3 \)

Normal force is generally equal to the __________ of an object.

61% Answer Correctly

	mass
	density
	coefficient of friction
	weight

Solution

Normal force arises on a flat horizontal surface in response to an object's weight pressing it down. Consequently, normal force is generally equal to the object's weight.

Concurrent forces:

55% Answer Correctly

	act in a common plane
	act along the same line of action
	pass through a common point
	act in a common dimension

Solution

Collinear forces act along the same line of action, concurrent forces pass through a common point and coplanar forces act in a common plane.

Sam can do 50 ft. lb. of work in 2 minutes and 5 seconds. What would Sam have to do to increase his power output?

64% Answer Correctly

	do the work in 3 minutes
	do 25 ft. lb. of work in 2 minutes 5 seconds
	do the work in 2 minutes
	do 100 ft. lb. of work in 4 minutes 12 seconds

Solution

Power is the rate of doing work or \(\frac{W}{t}\). To increase power, increase the work being done in the same amount of time or do the same amount of work in less time.

The principle of moments defines equilibrium in terms of:

53% Answer Correctly

	energy
	torque
	speed
	power

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.