ASVAB Mechanical Comprehension Practice Test 451487 Results

Your Results Global Average
Questions 5 5
Correct 0 3.39
Score 0% 68%

Review

1

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

61% Answer Correctly

low density

low corrosive action

chemically stable

high melting point


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.


2

What type of load acts on a relatively small area of a structure?

75% Answer Correctly

concentrated load

impact load

dynamic load

non-uniformly distributed load


Solution

A concentrated load acts on a relatively small area of a structure, a static uniformly distributed load doesn't create specific stress points or vary with time, a dynamic load varies with time or affects a structure that experiences a high degree of movement, an impact load is sudden and for a relatively short duration and a non-uniformly distributed load creates different stresses at different locations on a structure.


3

What defines the mechanical advantage of a first class lever?

65% Answer Correctly

position of the fulcrum

output force 

output distance

input force


Solution

A first-class lever is used to increase force or distance while changing the direction of the force. The lever pivots on a fulcrum and, when a force is applied to the lever at one side of the fulcrum, the other end moves in the opposite direction. The position of the fulcrum also defines the mechanical advantage of the lever. If the fulcrum is closer to the force being applied, the load can be moved a greater distance at the expense of requiring a greater input force. If the fulcrum is closer to the load, less force is required but the force must be applied over a longer distance. An example of a first-class lever is a seesaw / teeter-totter.


4

Which of these is the formula for kinetic energy?

67% Answer Correctly

\(KE = {1 \over 2}mh^2\)

\(KE = {1 \over 2}mv^2\)

\(KE = {m \over v^2 }\)

\(KE = mgh\)


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.


5

Two or more pulleys used together are called:

71% Answer Correctly

gears

third-class lever

wheel and axle

block and tackle


Solution

Two or more pulleys used together constitute a block and tackle which, unlike a fixed pulley, does impart mechanical advantage as a function of the number of pulleys that make up the arrangement.  So, for example, a block and tackle with three pulleys would have a mechanical advantage of three.