ASVAB Mechanical Comprehension Practice Test 175944 Results

Your Results Global Average
Questions 5 5
Correct 0 3.92
Score 0% 78%

Review

1 How much resistance could a 150 lb. effort force lift using a block and tackle pulley that has 4 ropes supporting the resistance?
82% Answer Correctly
540 lbs.
600 lbs.
601 lbs.
1200 lbs.
Solution

The mechanical advantage (MA) of a block and tackle pulley is equal to the number of times the effort force changes direction. An easy way to count how many times the effort force changes direction is to count the number of ropes that support the resistance which, in this problem, is 4. With a MA of 4, a 150 lbs. effort force could lift 150 lbs. x 4 = 600 lbs. resistance.

2

Potential energy is energy that has the potential to be converted into what?

81% Answer Correctly

 kinetic energy

power

heat

work
Solution

Potential energy is the energy of an object by virtue of its position relative to other objects. It is energy that has the potential to be converted into kinetic energy.

3

Which of these is the formula for force?

77% Answer Correctly

F = a/m

F = am2

F = m/a

F = ma
Solution

Newton's Second Law of Motion states that "The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object." This Law describes the linear relationship between mass and acceleration when it comes to force and leads to the formula F = ma or force equals mass multiplied by rate of acceleration.

4 If you lift a 3 lbs. rock 12 ft. from the ground, how much work have you done?
72% Answer Correctly
12 ft⋅lb
4 ft⋅lb
15 ft⋅lb
36 ft⋅lb
Solution
Work is force times distance. In this case, the force is the weight of the rock so:
\( W = F \times d \)
\( W = 3 \times 12 \)
\( W = 36 \)
5 What is the mechanical advantage of this inclined plane if the length of the ramp is 2 ft. and the height of the green box is 1 ft.?
82% Answer Correctly
3.5
1.8
2
5
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 = \( \frac{d_e}{d_r} \) = \( \frac{2 ft.}{1 ft.} \) = 2