ASVAB Mechanical Comprehension Practice Test 193514 Results

Your Results Global Average
Questions 5 5
Correct 0 3.23
Score 0% 65%

Review

1

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

81% Answer Correctly

9.8 m/s2

1 m/s2

6.67 x 10-11 m/s2

1 m/s
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

The mass of an object correlates to the size of the object but ultimately depends on:

66% Answer Correctly

the object's weight

gravity

the object's potential energy

the object's density
Solution

Mass is a measure of the amount of matter in an object.  In general, larger objects have larger mass than smaller objects but mass ultimately depends on how compact (dense) a substance is.

3 If the radius of the axle is 7 and the radius of the wheel is 8, what is the mechanical advantage of this wheel and axle configuration?
36% Answer Correctly
0
1
8
-1
Solution

The mechanical advantage of a wheel and axle lies in the difference in radius between the inner (axle) wheel and the outer wheel. But, this mechanical advantage is only realized when the input effort and load are applied to different wheels. Applying both input effort and load to the same wheel results in a mechanical advantage of 1.

4 If A = 4 ft. and the green box weighs 15 lbs. what is the torque acting on the A side of this lever?
74% Answer Correctly
0 ft⋅lb
240 ft⋅lb
60 ft⋅lb
15 ft⋅lb
Solution
For a lever, torque is weight x distance from the fulcrum which, in this case, is: 15 ft. x 4 lbs. = 60 ft⋅lb
5 If the green box weighs 30 lbs. and 10 lbs. of force is applied 3 ft. from the fulcrum at the blue arrow, how far from the fulcrum would the green box need to be placed to balance the lever?
55% Answer Correctly
2 ft.
4 ft.
0.5 ft.
1 ft.
Solution

To balance this lever the torques at the green box and the blue arrow must be equal. Torque is weight x distance from the fulcrum so the equation for equilibrium is:

Rada = Rbdb

where a represents the green box and b the blue arrow, R is resistance (weight/force) and d is the distance from the fulcrum.

Solving for da, our missing value, and plugging in our variables yields:

da = \( \frac{R_bd_b}{R_a} \) = \( \frac{10 lbs. \times 3 ft.}{30 lbs.} \) = \( \frac{30 ft⋅lb}{30 lbs.} \) = 1 ft.