ASVAB Mechanical Comprehension Practice Test 856272 Results

Your Results Global Average
Questions 5 5
Correct 0 3.36
Score 0% 67%

Review

1 If input effort is 700 ft⋅lb, what output effort will be produced by a machine with a mechanical advantage of 3?
79% Answer Correctly
4200ft⋅lb
525ft⋅lb
0ft⋅lb
2100 ft⋅lb
Solution
Mechanical advantage is the ratio of output force to input force and tells us by how many times a machine multiplies input effort. So, a machine with a mechanical advantage of 3 will multiply an input effort of 700 ft⋅lb by 3 to produce an output effort of 2100 ft⋅lb.
2

Which of the following is not a characteristic of a ceramic?

61% Answer Correctly

low corrosive action

chemically stable

low density

high melting point
Solution

Ceramics are mixtures of metallic and nonmetallic elements that withstand exteme thermal, chemical, and pressure environments. They have a high melting point, low corrosive action, and are chemically stable. Examples include rock, sand, clay, glass, brick, and porcelain.

3 The radius of the axle is 5, the radius of the wheel is 10, and the blue box weighs 80 lbs. What is the effort force necessary to balance the load?
53% Answer Correctly
20 lbs.
7 lbs.
40 lbs.
12 lbs.
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 10 and the output radius (where the resistance is being applied) is 5 for a mechanical advantage of \( \frac{10}{5} \) = 2.0

MA = \( \frac{load}{effort} \) so effort = \( \frac{load}{MA} \) = \( \frac{80 lbs.}{2.0} \) = 40 lbs.

4

On Earth, acceleration due to gravity (g) is approximately __________. 

81% Answer Correctly

6.67 x 10-11 m/s2

1 m/s2

1 m/s

9.8 m/s2
Solution

Newton's Law of Univeral Gravitation defines the general formula for the attraction of gravity between two objects:  \(\vec{F_{g}} = { Gm_{1}m_{2} \over r^2}\) . In the specific case of an object falling toward Earth, the acceleration due to gravity (g) is approximately 9.8 m/s2. 

5

The measure of how much of the power put into a machine is turned into movement or force is called:

56% Answer Correctly

power

mechanical advantage

force multiplication

efficiency
Solution

The efficiency of a machine describes how much of the power put into the machine is turned into movement or force. A 100% efficient machine would turn all of the input power into output movement or force. However, no machine is 100% efficient due to friction, heat, wear and other imperfections that consume input power without delivering any output.