ASVAB Mechanical Comprehension Practice Test 117834 Results

Your Results Global Average
Questions 5 5
Correct 0 3.28
Score 0% 66%

Review

1

Depending on where you apply effort and resistance, the wheel and axle can multiply:

45% Answer Correctly

force or distance

speed or power

power or distance

force or speed


Solution

If you apply the resistance to the axle and the effort to the wheel, the wheel and axle will multiply force and if you apply the resistance to the wheel and the effort to the axle, it will multiply speed.


2

If the handles of a wheelbarrow are 3 ft. from the wheel axle, what force must you exert to lift the handles if it's carrying a 270 lb. load concentrated at a point 0.5 ft. from the axle?

56% Answer Correctly

0.83 lbs

90 lbs

45 lbs

810 lbs


Solution

This problem describes a second-class lever and, for a second class lever, the effort force multiplied by the effort distance equals the resistance force multipied by the resistance distance: Fede = Frdr. Plugging in the variables from this problem yields:

Fe x 3 ft. = 270 lbs x 0.5 ft
Fe = 135 ft-lb. / 3 ft 
F= 45 lbs


3

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

74% 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.


4

Drag is a type of:

82% Answer Correctly

potential energy

friction

kinetic energy

work


Solution

Drag is friction that opposes movement through a fluid like liquid or air. The amount of drag depends on the shape and speed of the object with slower objects experiencing less drag than faster objects and more aerodynamic objects experiencing less drag than those with a large leading surface area.


5

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

69% Answer Correctly

second-class lever

inclined plane

first-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.