ASVAB Mechanical Comprehension Practice Test 843976 Results

Your Results Global Average
Questions 5 5
Correct 0 3.01
Score 0% 60%

Review

1 If the radius of the axle is 7 and the radius of the wheel is 10, what is the mechanical advantage of this wheel and axle configuration?
52% Answer Correctly
7
10
1.43
-3

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 7 for a mechanical advantage of \( \frac{10}{7} \) = 1.43


2

Assuming force applied remains constant, which of the following will result in more work being done?

53% Answer Correctly

moving the object farther

moving the object with more speed

increasing the coefficient of friction

moving the object with more acceleration


Solution

Work is accomplished when force is applied to an object: W = Fd where F is force in newtons (N) and d is distance in meters (m). Thus, the more force that must be applied to move an object, the more work is done and the farther an object is moved by exerting force, the more work is done.


3

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

76% Answer Correctly

higher than

lower than

opposite

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

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

pressure, density

pressure, volume

density, 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".


5

Which of the following represents how much two materials resist sliding across each other?

54% Answer Correctly

coefficient of friction

static friction

normal friction

kinetic friction


Solution

Coefficient of friction (μ) represents how much two materials resist sliding across each other.  Smooth surfaces like ice have low coefficients of friction while rough surfaces like concrete have high μ.