ASVAB Mechanical Comprehension Practice Test 191477 Results

Your Results Global Average
Questions 5 5
Correct 0 3.30
Score 0% 66%

Review

1

The standard unit of energy is the:

73% Answer Correctly

Joule

Watt

Volt

Horsepower
Solution

The Joule (J) is the standard unit of energy and has the unit \({kg \times m^2} \over s^2\).

2 If the green arrow in this diagram represents 180 ft⋅lb of work, how far will the box move if it weighs 90 pounds?
73% Answer Correctly
2 ft.
360 ft.
0 ft.
22 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:

Win = Wout
Feffort x deffort = Fresistance x dresistance

In this problem, the effort work is 180 ft⋅lb and the resistance force is 90 lbs. and we need to calculate the resistance distance:

Win = Fresistance x dresistance
180 ft⋅lb = 90 lbs. x dresistance
dresistance = \( \frac{180ft⋅lb}{90 lbs.} \) = 2 ft.

3 A = 4 ft., the green box weighs 35 lbs., and the blue box weighs 45 lbs. What does distance B need to be for this lever to balance?
65% Answer Correctly
12.44 ft.
3.11 ft.
11 ft.
6.22 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:

fAdA = fBdB

For this problem, the equation becomes:

35 lbs. x 4 ft. = 45 lbs. x dB

dB = \( \frac{35 \times 4 ft⋅lb}{45 lbs.} \) = \( \frac{140 ft⋅lb}{45 lbs.} \) = 3.11 ft.

4

When it comes to force, mass and acceleration have what kind of relationship?

65% Answer Correctly

inverse

exponential

logarithmic

linear
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.

5

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

54% Answer Correctly

static friction

coefficient of friction

kinetic 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.