ASVAB Mechanical Comprehension Practice Test 17978 Results

Your Results Global Average
Questions 5 5
Correct 0 3.67
Score 0% 73%

Review

1

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

80% Answer Correctly

power

work

heat

 kinetic energy
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.

2

The steering wheel of a car is an example of which type of simple machine?

88% Answer Correctly

block and tackle

wheel and axle

fixed pulley

first-class lever
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

Friction between two or more solid objects that are not moving relative to each other is called:

73% Answer Correctly

kinetic friction

dynamic friction

gravitational friction

static friction
Solution

Static friction is friction between two or more solid objects that are not moving relative to each other. An example is the friction that prevents a box on a sloped surface from sliding farther down the surface.

4 What is the efficiency of a machine has work input of 230 ft⋅lb and work output of 207 ft⋅lb?
67% Answer Correctly
45%
10%
180%
90%
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:
\( Efficiency = \frac{Work_{out}}{Work_{in}} \times 100 \) \( = \frac{207 ft⋅lb}{230 ft⋅lb} \times 100 \) \( = 90% \) %
5

Which of the following is not a type of simple machine?

58% Answer Correctly

pulley

lever

screw

gear
Solution

The six types of simple machines are the lever, wheel and axle, pulley, inclined plane, wedge, and screw.