ASVAB Mechanical Comprehension Practice Test 976565 Results

Your Results Global Average
Questions 5 5
Correct 0 2.65
Score 0% 53%

Review

1

Which of the following statements about drag is false?

58% Answer Correctly

slower objects experience more drag than faster objects

the amount of drag depends on the speed of an object

the amount of drag depends on the shape of an object

drag occurs during movement through a fluid


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.


2

An inclined plane increases ___________ to reduce ____________.

59% Answer Correctly

distance, power

force, power

force, distance

distance, force


Solution

An inclined plane is a simple machine that reduces the force needed to raise an object to a certain height. Work equals force x distance and, by increasing the distance that the object travels, an inclined plane reduces the force necessary to raise it to a particular height. In this case, the mechanical advantage is to make the task easier. An example of an inclined plane is a ramp.


3 If the radius of the axle is 3 and the radius of the wheel is 4, what is the mechanical advantage of this wheel and axle configuration?
52% Answer Correctly
0.75
-1
1.33
1

Solution

The mechanical advantage of a wheel and axle is the input radius divided by the output radius:

MA = \( \frac{r_i}{r_o} \)

In this case, the input radius (where the effort force is being applied) is 4 and the output radius (where the resistance is being applied) is 3 for a mechanical advantage of \( \frac{4}{3} \) = 1.33


4

For a hydraulic system, pressure applied to the input of the system will increase the pressure in which parts of the system?

58% Answer Correctly

everywhere in the system

the portions of the system at an altitude above the input

the portions of the system at an altitude below the input

all of these are correct


Solution

Pascal's law states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere. For a hydraulic system, this means that a pressure applied to the input of the system will increase the pressure everywhere in the system.


5

The advantage of using a third-class lever is that it increases:

37% Answer Correctly

the mechanical advantage of the lever

the distance traveled by the load

the force applied to the load

the speed of the load


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.