ASVAB Mechanical Comprehension Practice Test 435599 Results

Your Results Global Average
Questions 5 5
Correct 0 3.49
Score 0% 70%

Review

1 If input effort is 900 ft⋅lb, what output effort will be produced by a machine with a mechanical advantage of 5?
79% Answer Correctly
180ft⋅lb
4500 ft⋅lb
9000ft⋅lb
18000ft⋅lb
Solution
Mechanical advantage is the ratio of output force to input force and tells us by how many times a machine multiplies input effort. So, a machine with a mechanical advantage of 5 will multiply an input effort of 900 ft⋅lb by 5 to produce an output effort of 4500 ft⋅lb.
2 If the green box weighs 50 lbs. and is 3 ft. from the fulcrum, how much weight would need to be placed at the blue arrow to balance the lever if the arrow's distance from the fulcrum is 6 ft.?
63% Answer Correctly
8 lbs.
300 lbs.
50 lbs.
25 lbs.
Solution

To balance this lever the torques on each side of the fulcrum must be equal. Torque is weight x distance from the fulcrum so the equation for equilibrium is:

Rada = Rbdb

where a represents the left side of the fulcrum and b the right, R is resistance (weight) and d is the distance from the fulcrum.

Solving for Rb, our missing value, and plugging in our variables yields:

Rb = \( \frac{R_ad_a}{d_b} \) = \( \frac{50 lbs. \times 3 ft.}{6 ft.} \) = \( \frac{150 ft⋅lb}{6 ft.} \) = 25 lbs.

3

What type of load varies with time or affects a structure that experiences a high degree of movement?

66% Answer Correctly

impact load

dynamic load

concentrated load

static 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.

4

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

75% Answer Correctly

concentrated load

impact load

non-uniformly distributed load

dynamic 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.

5

Which of these is the formula for kinetic energy?

67% Answer Correctly

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

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

\(KE = mgh\)

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