ASVAB Mechanical Comprehension Practice Test 467151 Results

Your Results Global Average
Questions 5 5
Correct 0 3.05
Score 0% 61%

Review

1

The science that deals with motion and the forces that produce motion is called which of the following?

57% Answer Correctly

aeronautics

engineering

physics

mechanics
Solution

Mechanics deals with motion and the forces that produce motion.

2

The mechanical advantage of a wheel and axle is equal to the:

61% Answer Correctly

ratio of the diameters of the wheels

difference in the diameters of the wheels

length of the axle

difference in the lengths of the axles
Solution

A wheel and axle uses two different diameter wheels mounted to a connecting axle. Force is applied to the larger wheel and large movements of this wheel result in small movements in the smaller wheel. Because a larger movement distance is being translated to a smaller distance, force is increased with a mechanical advantage equal to the ratio of the diameters of the wheels. An example of a wheel and axle is the steering wheel of a car.

3 What is the efficiency of a machine has work input of 215 ft⋅lb and work output of 53 ft⋅lb?
67% Answer Correctly
50%
12%
100%
25%
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:
\( Efficiency = \frac{Work_{out}}{Work_{in}} \times 100 \) \( = \frac{53 ft⋅lb}{215 ft⋅lb} \times 100 \) \( = 25% \) %
4

Tension is a force that does which of the following?

75% Answer Correctly

stretches an object

slows an object

heats up an object

compacts 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

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

48% Answer Correctly

normal force

counter force

friction

mass
Solution

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