ASVAB Mechanical Comprehension Practice Test 359535 Results

Your Results Global Average
Questions 5 5
Correct 0 3.43
Score 0% 69%

Review

1

Power is the rate at which:

62% Answer Correctly

potential energy is converted into kinetic energy

work is done

input force is transferred to output force

friction is overcome
Solution

Power is the rate at which work is done, P = w/t, or work per unit time. The watt (W) is the unit for power and is equal to 1 joule (or newton-meter) per second. Horsepower (hp) is another familiar unit of power used primarily for rating internal combustion engines. 1 hp equals 746 watts.

2 A = 5 ft., the green box weighs 5 lbs., and the blue box weighs 50 lbs. What does distance B need to be for this lever to balance?
65% Answer Correctly
1 ft.
0.5 ft.
250 ft.
1.5 ft.
Solution
In order for this lever to balance, the torque acting on side A must equal the torque acting on side B. Torque is weight x distance from the fulcrum which means that the following must be true for the lever to balance:

fAdA = fBdB

For this problem, the equation becomes:

5 lbs. x 5 ft. = 50 lbs. x dB

dB = \( \frac{5 \times 5 ft⋅lb}{50 lbs.} \) = \( \frac{25 ft⋅lb}{50 lbs.} \) = 0.5 ft.

3

One Horsepower (hp) is equal to how many watts?

76% Answer Correctly

9.8

1

746

1492
Solution

Power is the rate at which work is done, P = w/t, or work per unit time. The watt (W) is the unit for power and is equal to 1 joule (or newton-meter) per second. Horsepower (hp) is another familiar unit of power used primarily for rating internal combustion engines. 1 hp equals 746 watts.

4

A box is resting on a smooth floor. Static friction is present:

59% Answer Correctly

at all times

when an attempt is made to move the box

if the coefficient of friction is greater than one

only if normal force is present
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).

5 What's the mechanical advantage of a wedge that's 3 inches wide and 9 inches long?
83% Answer Correctly
3
6
9
-6
Solution

The mechanical advantage (MA) of a wedge is its length divided by its thickness:

MA = \( \frac{l}{t} \) = \( \frac{9 in.}{3 in.} \) = 3