ASVAB Mechanical Comprehension Practice Test 464188 Results

Your Results Global Average
Questions 5 5
Correct 0 3.26
Score 0% 65%

Review

1

The steering wheel of a car is an example of which type of simple machine?

89% Answer Correctly

fixed pulley

first-class lever

block and tackle

wheel and axle


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.


2

A fixed pulley has a mechanical advantage of:

68% Answer Correctly

0

2

1

-1


Solution

A fixed pulley is used to change the direction of a force and does not multiply the force applied. As such, it has a mechanical advantage of one. The benefit of a fixed pulley is that it can allow the force to be applied at a more convenient angle, for example, pulling downward or horizontally to lift an object instead of upward.


3

A screw is most like which of the following other simple machines?

50% Answer Correctly

first-class lever

inclined plane

block and tackle

wheel and axle


Solution

A screw is an inclined plane wrapped in ridges (threads) around a cylinder. The distance between these ridges defines the pitch of the screw and this distance is how far the screw advances when it is turned once. The mechanical advantage of a screw is its circumference divided by the pitch.


4

What type of load creates different stresses at different locations on a structure?

60% Answer Correctly

static uniformly distributed load

non-uniformly distributed load

impact load

dynamic load


Solution

A concentrated load acts on a relatively small area of a structure, a static uniformly distributed load doesn't create specific stress points or vary with time, a dynamic load varies with time or affects a structure that experiences a high degree of movement, an impact load is sudden and for a relatively short duration and a non-uniformly distributed load creates different stresses at different locations on a structure.


5

Two gears are connected and the smaller gear drives the larger gear. The speed of rotation will __________ and the torque will __________.

61% Answer Correctly

increase, increase

increase, decrease

decrease, decrease

decrease, increase


Solution

Connected gears of different numbers of teeth are used together to change the rotational speed and torque of the input force. If the smaller gear drives the larger gear, the speed of rotation will be reduced and the torque will increase. If the larger gear drives the smaller gear, the speed of rotation will increase and the torque will be reduced.