ASVAB Mechanical Comprehension Practice Test 932735 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.37
Score	0%	67%

Review

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

76% Answer Correctly

	746
	9.8
	1
	1492

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.

Collinear forces:

73% Answer Correctly

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

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.

3 A 250 lb. barrel is rolled up a 17 ft. ramp to a platform that's 4 ft. tall. What effort is required to move the barrel?

53% Answer Correctly

	58.8 lbs.
	65.8 lbs.
	52.9 lbs.
	60.8 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 17 ft. = 250 lbs. x 4 ft.
F_e = \( \frac{1000 ft⋅lb}{17 ft.} \) = 58.8 lbs.

An object's resistance to changes in direction is known as:

82% Answer Correctly

	inertia
	kinetic energy
	weight
	mass

Solution

The more mass a substance has the more force is required to move it or to change its direction. This resistance to changes in direction is known as inertia.

5 If A = 11 ft., B = 1 ft., C = 8 ft., the green box weighs 35 lbs. and the blue box weighs 55 lbs., what does the orange box have to weigh for this lever to balance?

44% Answer Correctly

	41.25 lbs.
	3 lbs.
	20.63 lbs.
	165 lbs.

Solution

In order for this lever to balance, the torque acting on each side of the fulrum must be equal. So, the torque produced by A must equal the torque produced by B and C. Torque is weight x distance from the fulcrum which means that the following must be true for the lever to balance:

f_Ad_A = f_Bd_B + f_Cd_C

For this problem, this equation becomes:

35 lbs. x 11 ft. = 55 lbs. x 1 ft. + f_C x 8 ft.

385 ft. lbs. = 55 ft. lbs. + f_C x 8 ft.

f_C = \( \frac{385 ft. lbs. - 55 ft. lbs.}{8 ft.} \) = \( \frac{330 ft. lbs.}{8 ft.} \) = 41.25 lbs.