ASVAB Mechanical Comprehension Practice Test 82780 Results

Your Results Global Average
Questions 5 5
Correct 0 2.91
Score 0% 58%

Review

1

What is the first step to solving a problem where multiple forces are acting on an object?

61% Answer Correctly

calculate the total force

calculate potential energy

calculate kinetic energy

calculate the net force


Solution

In mechanics, multiple forces are often acting on a particular object and, taken together, produce the net force acting on that object. Like force, net force is a vector quantity in that it has magnitude and direction.


2

A wedge converts force applied to its blunt end into force __________ its inclined surface.

57% Answer Correctly

perpendicular to

parallel to

along

opposite to


Solution

The wedge is a moving inclined plane that is used to lift, hold, or break apart an object. A wedge converts force applied to its blunt end into force perpendicular to its inclined surface. In contrast to a stationary plane where force is applied to the object being moved, with a wedge the object is stationary and the force is being applied to the plane. Examples of a wedge include knives and chisels.


3

Gear ratio indicates which of the following about two connected gears?

59% Answer Correctly

mechanical advantage

efficiency

work done

power conversion


Solution

The mechanical advantage (amount of change in speed or torque) of connected gears is proportional to the number of teeth each gear has. Called gear ratio, it's the ratio of the number of teeth on the larger gear to the number of teeth on the smaller gear.  For example, a gear with 12 teeth connected to a gear with 9 teeth would have a gear ratio of 4:3.


4 If the radius of the axle is 5 and the radius of the wheel is 8, what is the mechanical advantage of this wheel and axle configuration?
53% Answer Correctly
1.6
3
0.63
5

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 8 and the output radius (where the resistance is being applied) is 5 for a mechanical advantage of \( \frac{8}{5} \) = 1.6


5

Which of the following will increase the mechanical advantage of this inclined plane?

59% Answer Correctly

shorten the ramp

lower the force acting at the blue arrow

lengthen the ramp

increase the force acting at the blue arrow


Solution

The mechanical advantage (MA) of an inclined plane is the effort distance divided by the resistance distance. In order to increase mechanical advantage, this ratio must increase which means making the effort distance longer and this can be accomplished by lengthening the length of the ramp.