ASVAB Mechanical Comprehension Practice Test 258637 Results

Your Results Global Average
Questions 5 5
Correct 0 3.52
Score 0% 70%

Review

1

Which of the following is not a modulus of elasticity?

47% Answer Correctly

stretch modulus

bulk modulus

stress modulus

shear modulus


Solution

The modulus of elasticity measures how much a material or structure will deflect under stress. Stretch modulus is longitudinal stretch (like stretching raw bread dough), shear modulus is longitudinal deflection (like the horizontal displacement of a stack of magzines when a heavy object is placed upon them), and bulk modulus is compression of volume (like the compression of a loaf of bread under a heavy can at the bottom of a grocery bag).


2

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

76% Answer Correctly

1492

1

746

9.8


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.


3

A ramp is an example of which kind of simple machine?

84% Answer Correctly

none of these

inclined plane

first-class lever

wedge


Solution

An inclined plane is a simple machine that reduces the force needed to raise an object to a certain height. Work equals force x distance and, by increasing the distance that the object travels, an inclined plane reduces the force necessary to raise it to a particular height. In this case, the mechanical advantage is to make the task easier. An example of an inclined plane is a ramp.


4

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

61% Answer Correctly

decrease, increase

increase, decrease

increase, increase

decrease, decrease


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.


5

Which of the following surfaces would have the lowest coefficient of friction?

85% Answer Correctly

leather

concrete

ice

tile


Solution

Coefficient of friction (μ) represents how much two materials resist sliding across each other.  Smooth surfaces like ice have low coefficients of friction while rough surfaces like concrete have high μ.