ASVAB Mechanical Comprehension Practice Test 319668 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.10
Score	0%	62%

Review

Which of the following is not a characteristic of a ceramic?

61% Answer Correctly

	low corrosive action
	high melting point
	low density
	chemically stable

Solution

Ceramics are mixtures of metallic and nonmetallic elements that withstand exteme thermal, chemical, and pressure environments. They have a high melting point, low corrosive action, and are chemically stable. Examples include rock, sand, clay, glass, brick, and porcelain.

2 If A = 7 ft. and the green box weighs 40 lbs. what is the torque acting on the A side of this lever?

75% Answer Correctly

	560 ft⋅lb
	280 ft⋅lb
	5 ft⋅lb
	70 ft⋅lb

Solution

For a lever, torque is weight x distance from the fulcrum which, in this case, is: 40 ft. x 7 lbs. = 280 ft⋅lb

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

53% Answer Correctly

	kinetic friction
	coefficient of friction
	static 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.

A fixed pulley has a mechanical advantage of:

68% Answer Correctly

	0
	1
	-1
	2

Solution

A fixed pulley is used to change the direction of a force and does not multiply the force applied. As such, it has a mechanical advantage of one. The benefit of a fixed pulley is that it can allow the force to be applied at a more convenient angle, for example, pulling downward or horizontally to lift an object instead of upward.

5 A 490 lb. barrel is rolled up a 10 ft. ramp to a platform that's 4 ft. tall. What effort is required to move the barrel?

53% Answer Correctly

	196 lbs.
	392 lbs.
	98 lbs.
	176.4 lbs.

Solution

This problem describes an inclined plane and, for an inclined plane, the effort force multiplied by the effort distance equals the resistance force multipied by the resistance distance:

F_ed_e = F_rd_r

Plugging in the variables from this problem yields:

F_e x 10 ft. = 490 lbs. x 4 ft.
F_e = \( \frac{1960 ft⋅lb}{10 ft.} \) = 196 lbs.