ASVAB Mechanical Comprehension Practice Test 439427 Results

Your Results Global Average
Questions 5 5
Correct 0 3.68
Score 0% 74%

Review

1

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

82% Answer Correctly

1 m/s

6.67 x 10-11 m/s2

1 m/s2

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. 

2 If input effort is 600 ft⋅lb, what output effort will be produced by a machine with a mechanical advantage of 8?
79% Answer Correctly
9600ft⋅lb
4800 ft⋅lb
19200ft⋅lb
0ft⋅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 8 will multiply an input effort of 600 ft⋅lb by 8 to produce an output effort of 4800 ft⋅lb.
3

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

61% Answer Correctly

calculate the net force

calculate the total force

calculate potential energy

calculate kinetic energy
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.

4 A = 5 ft., the green box weighs 20 lbs., and the blue box weighs 55 lbs. What does distance B need to be for this lever to balance?
65% Answer Correctly
275 ft.
3.64 ft.
1.82 ft.
11 ft.
Solution
In order for this lever to balance, the torque acting on side A must equal the torque acting on side B. Torque is weight x distance from the fulcrum which means that the following must be true for the lever to balance:

fAdA = fBdB

For this problem, the equation becomes:

20 lbs. x 5 ft. = 55 lbs. x dB

dB = \( \frac{20 \times 5 ft⋅lb}{55 lbs.} \) = \( \frac{100 ft⋅lb}{55 lbs.} \) = 1.82 ft.

5 What's the mechanical advantage of a wedge that's 5 inches wide and 15 inches long?
83% Answer Correctly
4.5
3
1
-6
Solution

The mechanical advantage (MA) of a wedge is its length divided by its thickness:

MA = \( \frac{l}{t} \) = \( \frac{15 in.}{5 in.} \) = 3