ASVAB Mechanical Comprehension Practice Test 874559 Results

Your Results Global Average
Questions 5 5
Correct 0 3.22
Score 0% 64%

Review

1

The mass of an object correlates to the size of the object but ultimately depends on:

67% Answer Correctly

the object's weight

gravity

the object's potential energy

the object's density


Solution

Mass is a measure of the amount of matter in an object.  In general, larger objects have larger mass than smaller objects but mass ultimately depends on how compact (dense) a substance is.


2

What's the first gear in a gear train called?

58% Answer Correctly

idler gear

input gear

driven gear

driver gear


Solution

A gear train is two or more gears linked together. Gear trains are designed to increase or reduce the speed or torque outpout of a rotating system or change the direction of its output. The first gear in the chain is called the driver and the last gear in the chain the driven gear with the gears between them called idler gears.


3 If A = 4 ft. and the green box weighs 20 lbs. what is the torque acting on the A side of this lever?
76% Answer Correctly
240 ft⋅lb
80 ft⋅lb
26 ft⋅lb
5 ft⋅lb

Solution
For a lever, torque is weight x distance from the fulcrum which, in this case, is: 20 ft. x 4 lbs. = 80 ft⋅lb

4

The principle of conservation of mechanical energy states that, as long as no other forces are applied, what will remain constant as an object falls?

45% Answer Correctly

kinetic energy

potential energy

total mechanical energy

acceleration


Solution

As an object falls, its potential energy is converted into kinetic energy. The principle of conservation of mechanical energy states that, as long as no other forces are applied, total mechanical energy (PE + KE) of the object will remain constant at all points in its descent.


5 If you have a gear train with two gears, the first with 20 teeth and the second with 16 teeth, how many revolutions does the second gear make for each revolution of the first gear?
78% Answer Correctly
1.4
1.1
4.3
1.3

Solution

The gear ratio (Vr) of a gear train is the product of the gear ratios between the pairs of meshed gears. Let N represent the number of teeth for each gear:

Vr = \( \frac{N_1}{N_2} \) \( \frac{N_2}{N_3} \) \( \frac{N_3}{N_4} \) ... \( \frac{N_n}{N_{n+1}} \)

In this problem, we have only two gears so the equation becomes:

Vr = \( \frac{N_1}{N_2} \) = \( \frac{20}{16} \) = 1.3