ASVAB Mechanical Comprehension Practice Test 222032 Results

Your Results Global Average
Questions 5 5
Correct 0 2.95
Score 0% 59%

Review

1 If 35 lbs. of force is applied 5 ft. from the fulcrum at the blue arrow and the green box is 2 ft. from the fulcrum, how much would the green box have to weigh to balance the lever?
62% Answer Correctly
87.5 lbs.
0 lbs.
175 lbs.
29.17 lbs.
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 Ra, our missing value, and plugging in our variables yields:

Ra = \( \frac{R_bd_b}{d_a} \) = \( \frac{35 lbs. \times 5 ft.}{2 ft.} \) = \( \frac{175 ft⋅lb}{2 ft.} \) = 87.5 lbs.

2

According to Boyle's law, for a fixed amount of gas kept at a fixed temperature, which of the following are inversely proportional?

63% Answer Correctly

density, volume

pressure, density

pressure, volume

volume, mass
Solution

Boyle's law states that "for a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional".

3

The force required to initally get an object moving is __________ the force required to keep it moving. 

76% Answer Correctly

opposite

higher than

lower than

the same as
Solution

For any given surface, the coefficient of static friction is higher than the coefficient of kinetic friction. More force is required to initally get an object moving than is required to keep it moving. Additionally, static friction only arises in response to an attempt to move an object (overcome the normal force between it and the surface).

4 If the radius of the axle is 3 and the radius of the wheel is 4, what is the mechanical advantage of this wheel and axle configuration?
36% Answer Correctly
-1
3
1
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.

5

For any given surface, the coefficient of static friction is ___________ the coefficient of kinetic friction.

54% Answer Correctly

higher than

equal to

opposite

lower than
Solution

For any given surface, the coefficient of static friction is higher than the coefficient of kinetic friction. More force is required to initally get an object moving than is required to keep it moving. Additionally, static friction only arises in response to an attempt to move an object (overcome the normal force between it and the surface).