ASVAB Mechanical Comprehension Practice Test 972554 Results

Your Results Global Average
Questions 5 5
Correct 0 2.73
Score 0% 55%

Review

1

Which of the following is the formula for torque?

61% Answer Correctly

τ = rF

τ = F/r2

τ = F/r

τ = r/F


Solution

Torque measures force applied during rotation: τ = rF.  Torque (τ, the Greek letter tau) = the radius of the lever arm (r) multiplied by the force (F) applied. Radius is measured from the center of rotation or fulcrum to the point at which the perpendicular force is being applied. The resulting unit for torque is newton-meter (N-m) or foot-pound (ft-lb).


2

Lisa lifts a 25 pound box from the floor onto a loading dock 4 ft. off the ground. Sam slides the same box along a ramp to move it up another 4 ft. onto a flatbed truck. Who has done more work?

50% Answer Correctly

Sam

Neither have done any work

Lisa

They have done an equal amount of work


Solution

Work is force multiplied by distance. Because both Connie and Sam moved the same weight the same distance they have done an equal amount of work. Sam employed the mechnacial advantage of an inclined plane so he exerted less effort to do the work but the amount of work done was still the same.


3

Which of the following is not a type of structural load?

50% Answer Correctly

wind load

dead load

occupancy load

live load


Solution

Dead load is the weight of the building and materials, live load is additional weight due to occupancy or use, snow load is the weight of accumulated snow on a structure and wind load is the force of wind pressures against structure surfaces.


4

The principle of conservation of mechanical energy states that, as long as no other forces are applied, what will remain constant as an object falls?

45% Answer Correctly

acceleration

kinetic energy

total mechanical energy

potential energy


Solution

As an object falls, its potential energy is converted into kinetic energy. The principle of conservation of mechanical energy states that, as long as no other forces are applied, total mechanical energy (PE + KE) of the object will remain constant at all points in its descent.


5

A a seesaw / teeter-totter is an example of which of the following?

69% Answer Correctly

first-class lever

inclined plane

second-class lever

third-class lever


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.