ASVAB Mechanical Comprehension Practice Test 775204 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.82
Score	0%	56%

Review

Lisa lifts a 25 pound box from the floor onto a loading dock 4 ft. off the ground. Sam slides the same box along a ramp to move it up another 4 ft. onto a flatbed truck. Who has done more work?

50% Answer Correctly

	They have done an equal amount of work
	Neither have done any work
	Sam
	Lisa

Solution

Work is force multiplied by distance. Because both Connie and Sam moved the same weight the same distance they have done an equal amount of work. Sam employed the mechnacial advantage of an inclined plane so he exerted less effort to do the work but the amount of work done was still the same.

2 If the radius of the axle is 5 and the radius of the wheel is 10, what is the mechanical advantage of this wheel and axle configuration?

36% Answer Correctly

	0
	1
	2
	5

Solution

The mechanical advantage of a wheel and axle lies in the difference in radius between the inner (axle) wheel and the outer wheel. But, this mechanical advantage is only realized when the input effort and load are applied to different wheels. Applying both input effort and load to the same wheel results in a mechanical advantage of 1.

Gear ratio indicates which of the following about two connected gears?

59% Answer Correctly

	power conversion
	mechanical advantage
	efficiency
	work done

Solution

The mechanical advantage (amount of change in speed or torque) of connected gears is proportional to the number of teeth each gear has. Called gear ratio, it's the ratio of the number of teeth on the larger gear to the number of teeth on the smaller gear. For example, a gear with 12 teeth connected to a gear with 9 teeth would have a gear ratio of 4:3.

The measure of how much of the power put into a machine is turned into movement or force is called:

56% Answer Correctly

	power
	force multiplication
	efficiency
	mechanical advantage

Solution

The efficiency of a machine describes how much of the power put into the machine is turned into movement or force. A 100% efficient machine would turn all of the input power into output movement or force. However, no machine is 100% efficient due to friction, heat, wear and other imperfections that consume input power without delivering any output.

5 What's the mechanical advantage of a wedge that's 3 inches wide and 24 inches long?

83% Answer Correctly

	4
	8
	9.5
	10

Solution

The mechanical advantage (MA) of a wedge is its length divided by its thickness:

MA = \( \frac{l}{t} \) = \( \frac{24 in.}{3 in.} \) = 8