ASVAB Mechanical Comprehension Practice Test 763484 Results

Your Results Global Average
Questions 5 5
Correct 0 3.12
Score 0% 62%

Review

1

A truck is using a rope to pull a car. Tension in the rope is greatest in which of the following places?

50% Answer Correctly

in the middle

tension is equal in all parts of the rope

near the car

near the truck
Solution

Tension is a force that stretches or elongates something. When a cable or rope is used to pull an object, for example, it stretches internally as it accepts the weight that it's moving. Although tension is often treated as applying equally to all parts of a material, it's greater at the places where the material is under the most stress.

2 If the radius of the axle is 7 and the radius of the wheel is 12, what is the mechanical advantage of this wheel and axle configuration?
36% Answer Correctly
0
7
12
1
Solution

The mechanical advantage of a wheel and axle lies in the difference in radius between the inner (axle) wheel and the outer wheel. But, this mechanical advantage is only realized when the input effort and load are applied to different wheels. Applying both input effort and load to the same wheel results in a mechanical advantage of 1.

3 What is the efficiency of a machine has work input of 235 ft⋅lb and work output of 117 ft⋅lb?
68% Answer Correctly
100%
50%
0%
2%
Solution
Due to friction, a machine will never be able to utilize 100% of its work input. A certain percentage of that input will be lost in overcoming friction within the machine. Effeciency is a measure of how much of a machine's work input can be turned into useful work output and is calculated by dividing work output by work input and multiplying the result by 100:
\( Efficiency = \frac{Work_{out}}{Work_{in}} \times 100 \) \( = \frac{117 ft⋅lb}{235 ft⋅lb} \times 100 \) \( = 50% \) %
4

Tension is a force that does which of the following?

76% Answer Correctly

stretches an object

compacts an object

slows an object

heats up an object
Solution

Tension is a force that stretches or elongates something. When a cable or rope is used to pull an object, for example, it stretches internally as it accepts the weight that it's moving. Although tension is often treated as applying equally to all parts of a material, it's greater at the places where the material is under the most stress.

5

When all forces acting on a system cancel each other out, this is called:

81% Answer Correctly

potential energy

equilibrium

stasis

rest
Solution

When a system is stable or balanced (equilibrium) all forces acting on the system cancel each other out. In the case of torque, equilibrium means that the sum of the anticlockwise moments about a center of rotation equal the sum of the clockwise moments.