ASVAB Mechanical Comprehension Practice Test 740104 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.44
Score	0%	69%

Review

1 What is the efficiency of a machine has work input of 110 ft⋅lb and work output of 104 ft⋅lb?

68% Answer Correctly

	380%
	95%
	23%
	5%

Solution

Due to friction, a machine will never be able to utilize 100% of its work input. A certain percentage of that input will be lost in overcoming friction within the machine. Effeciency is a measure of how much of a machine's work input can be turned into useful work output and is calculated by dividing work output by work input and multiplying the result by 100:
\( Efficiency = \frac{Work_{out}}{Work_{in}} \times 100 \) \( = \frac{104 ft⋅lb}{110 ft⋅lb} \times 100 \) \( = 95% \) %

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

62% Answer Correctly

	weight
	density
	mass
	coefficient of friction

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.

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

67% Answer Correctly

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

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.

Collinear forces:

73% Answer Correctly

	pass through a common point
	act along the same line of action
	are unrelated to each other
	act in a common plane

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.

One Horsepower (hp) is equal to how many watts?

76% Answer Correctly

	746
	9.8
	1492
	1

Solution

Power is the rate at which work is done, P = w/t, or work per unit time. The watt (W) is the unit for power and is equal to 1 joule (or newton-meter) per second. Horsepower (hp) is another familiar unit of power used primarily for rating internal combustion engines. 1 hp equals 746 watts.