ASVAB Mechanical Comprehension Practice Test 7393 Results

Your Results Global Average
Questions 5 5
Correct 0 2.91
Score 0% 58%

Review

1 A 470 lb. barrel is rolled up a 14 ft. ramp to a platform that's 2 ft. tall. What effort is required to move the barrel?
53% Answer Correctly
134.3 lbs.
67.1 lbs.
62.1 lbs.
22.4 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 14 ft. = 470 lbs. x 2 ft.
Fe = \( \frac{940 ft⋅lb}{14 ft.} \) = 67.1 lbs.


2

Collinear forces:

73% Answer Correctly

pass through a common point

are unrelated to each other

act along the same line of action

act in a common plane


Solution

Collinear forces act along the same line of action, concurrent forces pass through a common point and coplanar forces act in a common plane.


3

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

54% Answer Correctly

equal to

opposite

lower than

higher than


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

A block and tackle with four pulleys would have a mechanical advantage of:

79% Answer Correctly

1

2

0

4


Solution

Two or more pulleys used together constitute a block and tackle which, unlike a fixed pulley, does impart mechanical advantage as a function of the number of pulleys that make up the arrangement.  So, for example, a block and tackle with three pulleys would have a mechanical advantage of three.


5

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

38% Answer Correctly

driver gear

driven gear

idler gear

output 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.