ASVAB Mechanical Comprehension Practice Test 318341 Results

Your Results Global Average
Questions 5 5
Correct 0 3.62
Score 0% 72%

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

the portions of the system at an altitude below the input

everywhere in the system

the portions of the system at an altitude above 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

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

76% Answer Correctly

the same as

higher than

lower 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).


3

The mechanical advantage of a wheel and axle is equal to the:

61% Answer Correctly

difference in the diameters of the wheels

ratio of the diameters of the wheels

length of the axle

difference in the lengths of the axles


Solution

A wheel and axle uses two different diameter wheels mounted to a connecting axle. Force is applied to the larger wheel and large movements of this wheel result in small movements in the smaller wheel. Because a larger movement distance is being translated to a smaller distance, force is increased with a mechanical advantage equal to the ratio of the diameters of the wheels. An example of a wheel and axle is the steering wheel of a car.


4

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

81% Answer Correctly

9.8 m/s2

1 m/s

6.67 x 10-11 m/s2

1 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


5

Friction resists movement in a direction __________ to the movement.

81% Answer Correctly

perpendicular

opposite

parallel

normal


Solution

Friction resists movement. Kinetic (also called sliding or dynamic) friction resists movement in a direction opposite to the movement. Because it opposes movement, kinetic friction will eventually bring an object to a stop. An example is a rock that's sliding across ice.