ASVAB Mechanical Comprehension Practice Test 490935 Results

Your Results Global Average
Questions 5 5
Correct 0 3.04
Score 0% 61%

Review

1

For a hydraulic system, pressure applied to the input of the system will increase the pressure in which parts of the system?

58% Answer Correctly

all of these are correct

everywhere in the system

the portions of the system at an altitude above the input

the portions of the system at an altitude below the input


Solution

Pascal's law states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere. For a hydraulic system, this means that a pressure applied to the input of the system will increase the pressure everywhere in the system.


2

Normal force is generally equal to the __________ of an object.

62% Answer Correctly

density

mass

coefficient of friction

weight


Solution

Normal force arises on a flat horizontal surface in response to an object's weight pressing it down. Consequently, normal force is generally equal to the object's weight.


3

Tension is a force that does which of the following?

76% Answer Correctly

stretches an object

slows an object

heats up an object

compacts an object


Solution

Tension is a force that stretches or elongates something. When a cable or rope is used to pull an object, for example, it stretches internally as it accepts the weight that it's moving. Although tension is often treated as applying equally to all parts of a material, it's greater at the places where the material is under the most stress.


4 A 380 lb. barrel is rolled up a 8 ft. ramp to a platform that's 4 ft. tall. What effort is required to move the barrel?
53% Answer Correctly
171 lbs.
190 lbs.
186 lbs.
194 lbs.

Solution

This problem describes an inclined plane and, for an inclined plane, the effort force multiplied by the effort distance equals the resistance force multipied by the resistance distance:

Fede = Frdr

Plugging in the variables from this problem yields:

Fe x 8 ft. = 380 lbs. x 4 ft.
Fe = \( \frac{1520 ft⋅lb}{8 ft.} \) = 190 lbs.


5

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

54% Answer Correctly

equal to

lower than

higher than

opposite


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).