ASVAB Mechanical Comprehension Practice Test 909896 Results

Your Results Global Average
Questions 5 5
Correct 0 2.96
Score 0% 59%

Review

1

The steering wheel of a car is an example of which type of simple machine?

89% Answer Correctly

wheel and axle

fixed pulley

block and tackle

first-class lever
Solution

A wheel and axle uses two different diameter wheels mounted to a connecting axle. Force is applied to the larger wheel and large movements of this wheel result in small movements in the smaller wheel. Because a larger movement distance is being translated to a smaller distance, force is increased with a mechanical advantage equal to the ratio of the diameters of the wheels. An example of a wheel and axle is the steering wheel of a car.

2

Which of the following is not a type of simple machine?

58% Answer Correctly

pulley

lever

screw

gear
Solution

The six types of simple machines are the lever, wheel and axle, pulley, inclined plane, wedge, and screw.

3 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?
41% Answer Correctly
0.63
8
1.6
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 5 and the output radius (where the resistance is being applied) is 8 for a mechanical advantage of \( \frac{5}{8} \) = 0.63

4 If the handles of a wheelbarrow are 1.5 ft. from the wheel axle and the load is concentrated at a point 1.0 ft. from the axle, how many pounds of load will a 220 lbs. force lift?
47% Answer Correctly
96.1
220
330
-85.8
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. In this problem we're looking for resistance force:
\( F_r = \frac{F_e d_e}{d_r} \)
\( F_r = \frac{220 \times 1.5}{1.0} \)
\( F_r = \frac{330.0}{1.0} \)
\( F_r = 330 \)
5

Which of the following is the formula for hydraulic pressure?

58% Answer Correctly

P = FA2

P = F/A

P = FA

P = F/A2
Solution

Hydraulics is the transmission of force through the use of liquids. Liquids are especially suited for transferring force in complex machines because they compress very little and can occupy very small spaces. Hydraulic pressure is calculated by dividing force by the area over which it is applied: P = F/A where F is force in pounds, A is area in square inches, and the resulting pressure is in pounds per square inch (psi).