ASVAB Mechanical Comprehension Practice Test 851191 Results

Your Results Global Average
Questions 5 5
Correct 0 2.92
Score 0% 58%

Review

1

Which of the following will increase the mechanical advantage of this inclined plane?

59% Answer Correctly

lower the force acting at the blue arrow

shorten the ramp

lengthen the ramp

increase the force acting at the blue arrow


Solution

The mechanical advantage (MA) of an inclined plane is the effort distance divided by the resistance distance. In order to increase mechanical advantage, this ratio must increase which means making the effort distance longer and this can be accomplished by lengthening the length of the ramp.


2

Which of the following is not a characteristic of a ceramic?

61% Answer Correctly

high melting point

chemically stable

low corrosive action

low density


Solution

Ceramics are mixtures of metallic and nonmetallic elements that withstand exteme thermal, chemical, and pressure environments. They have a high melting point, low corrosive action, and are chemically stable. Examples include rock, sand, clay, glass, brick, and porcelain.


3

Which of these will have the most impact on the kinetic energy of an object?

54% Answer Correctly

its speed

its direction

its mass

its weight


Solution

Kinetic energy is the energy of movement and is a function of the mass of an object and its speed: \(KE = {1 \over 2}mv^2\) where m is mass in kilograms, v is speed in meters per second, and KE is in joules. The most impactful quantity to kinetic energy is velocity as an increase in mass increases KE linearly while an increase in speed increases KE exponentially.


4

Power is the rate at which:

62% Answer Correctly

potential energy is converted into kinetic energy

friction is overcome

input force is transferred to output force

work is done


Solution

Power is the rate at which work is done, P = w/t, or work per unit time. The watt (W) is the unit for power and is equal to 1 joule (or newton-meter) per second. Horsepower (hp) is another familiar unit of power used primarily for rating internal combustion engines. 1 hp equals 746 watts.


5

A shovel is an example of which class of lever?

56% Answer Correctly

a shovel is not a lever

second

third

first


Solution

A third-class lever is used to increase distance traveled by an object in the same direction as the force applied. The fulcrum is at one end of the lever, the object at the other, and the force is applied between them. This lever does not impart a mechanical advantage as the effort force must be greater than the load but does impart extra speed to the load. Examples of third-class levers are shovels and tweezers.