ASVAB Mechanical Comprehension Practice Test 635122 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.31
Score	0%	66%

Review

The principle of conservation of mechanical energy states that, as long as no other forces are applied, what will remain constant as an object falls?

45% Answer Correctly

	potential energy
	total mechanical energy
	kinetic energy
	acceleration

Solution

As an object falls, its potential energy is converted into kinetic energy. The principle of conservation of mechanical energy states that, as long as no other forces are applied, total mechanical energy (PE + KE) of the object will remain constant at all points in its descent.

2 If the green arrow in this diagram represents 400 ft⋅lb of work, how far will the box move if it weighs 100 pounds?

72% Answer Correctly

	16 ft.
	4 ft.
	8 ft.
	400 ft.

Solution

The Law of Work states that the work put into a machine is equal to the work received from the machine under ideal conditions. In equation form, that's:

W_in = W_out
F_effort x d_effort = F_resistance x d_resistance

In this problem, the effort work is 400 ft⋅lb and the resistance force is 100 lbs. and we need to calculate the resistance distance:

W_in = F_resistance x d_resistance
400 ft⋅lb = 100 lbs. x d_resistance
d_resistance = \( \frac{400ft⋅lb}{100 lbs.} \) = 4 ft.

Which of the following represents the force a surface exerts when an object presses against it?

48% Answer Correctly

	friction
	counter force
	normal force
	mass

Solution

Normal force (F_N) represents the force a surface exerts when an object presses against it.

4 What is the mechanical advantage of this inclined plane if the length of the ramp is 72 ft. and the height of the green box is 8 ft.?

82% Answer Correctly

	11
	4
	27
	9

Solution

The mechanical advantage (MA) of an inclined plane is the effort distance divided by the resistance distance. In this case, the effort distance is the length of the ramp and the resistance distance is the height of the green box:

MA = \( \frac{d_e}{d_r} \) = \( \frac{72 ft.}{8 ft.} \) = 9

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

82% Answer Correctly

	inertia
	kinetic energy
	mass
	weight

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.