ASVAB Mechanical Comprehension Practice Test 221167 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.95
Score	0%	59%

Review

1 If the radius of the axle is 3 and the radius of the wheel is 6, what is the mechanical advantage of this wheel and axle configuration?

52% Answer Correctly

	-3
	0.5
	2.0
	6

Solution

The mechanical advantage of a wheel and axle is the input radius divided by the output radius:

MA = \( \frac{r_i}{r_o} \)

In this case, the input radius (where the effort force is being applied) is 6 and the output radius (where the resistance is being applied) is 3 for a mechanical advantage of \( \frac{6}{3} \) = 2.0

Drag is a type of:

81% Answer Correctly

	potential energy
	work
	kinetic energy
	friction

Solution

Drag is friction that opposes movement through a fluid like liquid or air. The amount of drag depends on the shape and speed of the object with slower objects experiencing less drag than faster objects and more aerodynamic objects experiencing less drag than those with a large leading surface area.

3 If the handles of a wheelbarrow are 1.0 ft. from the wheel axle and the load is concentrated at a point 1.0 ft. from the axle, how many pounds of load will a 220 lbs. force lift?

47% Answer Correctly

	53.9
	0
	-89
	220

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:
\( F_r = \frac{F_e d_e}{d_r} \)
\( F_r = \frac{220 \times 1.0}{1.0} \)
\( F_r = \frac{220.0}{1.0} \)
\( F_r = 220 \)

What is work?

60% Answer Correctly

	Force per unit distance
	Force per unit time
	The movement of an object by a force
	The potential for exertion

Solution

Work is accomplished when force is applied to an object: W = Fd where F is force in newtons (N) and d is distance in meters (m). Thus, the more force that must be applied to move an object, the more work is done and the farther an object is moved by exerting force, the more work is done. By definition, work is the displacement of an object resulting from applied force.

Which of the following represents how much two materials resist sliding across each other?

53% Answer Correctly

	static friction
	coefficient of friction
	kinetic friction
	normal friction

Solution

Coefficient of friction (μ) represents how much two materials resist sliding across each other. Smooth surfaces like ice have low coefficients of friction while rough surfaces like concrete have high μ.