ASVAB Mechanical Comprehension Practice Test 133025 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.77
Score	0%	55%

Review

An inclined plane increases ___________ to reduce ____________.

58% Answer Correctly

	force, power
	distance, power
	force, distance
	distance, force

Solution

An inclined plane is a simple machine that reduces the force needed to raise an object to a certain height. Work equals force x distance and, by increasing the distance that the object travels, an inclined plane reduces the force necessary to raise it to a particular height. In this case, the mechanical advantage is to make the task easier. An example of an inclined plane is a ramp.

Depending on where you apply effort and resistance, the wheel and axle can multiply:

45% Answer Correctly

	speed or power
	power or distance
	force or distance
	force or speed

Solution

If you apply the resistance to the axle and the effort to the wheel, the wheel and axle will multiply force and if you apply the resistance to the wheel and the effort to the axle, it will multiply speed.

The work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. This defines which of the following?

60% Answer Correctly

	conservation of mechanical energy
	work-energy theorem
	mechanical advantage
	Pascal's law

Solution

The work-energy theorem states that the work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. Simply put, work imparts kinetic energy to the matter upon which the work is being done.

A screw is most like which of the following other simple machines?

50% Answer Correctly

	block and tackle
	wheel and axle
	first-class lever
	inclined plane

Solution

A screw is an inclined plane wrapped in ridges (threads) around a cylinder. The distance between these ridges defines the pitch of the screw and this distance is how far the screw advances when it is turned once. The mechanical advantage of a screw is its circumference divided by the pitch.

5 A = 7 ft., the green box weighs 15 lbs., and the blue box weighs 60 lbs. What does distance B need to be for this lever to balance?

65% Answer Correctly

	2 ft.
	420 ft.
	3.5 ft.
	1.75 ft.

Solution

In order for this lever to balance, the torque acting on side A must equal the torque acting on side B. 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

For this problem, the equation becomes:

15 lbs. x 7 ft. = 60 lbs. x d_B

d_B = \( \frac{15 \times 7 ft⋅lb}{60 lbs.} \) = \( \frac{105 ft⋅lb}{60 lbs.} \) = 1.75 ft.