ASVAB Mechanical Comprehension Practice Test 6339 Results

Your Results Global Average
Questions 5 5
Correct 0 3.11
Score 0% 62%

Review

1

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

60% Answer Correctly

non-uniformly distributed load

impact load

dynamic load

static uniformly distributed 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.


2

Which of the following is not a characteristic of a ceramic?

61% Answer Correctly

chemically stable

low corrosive action

high melting point

low density


Solution

Ceramics are mixtures of metallic and nonmetallic elements that withstand exteme thermal, chemical, and pressure environments. They have a high melting point, low corrosive action, and are chemically stable. Examples include rock, sand, clay, glass, brick, and porcelain.


3

Which of the following is not a modulus of elasticity?

47% Answer Correctly

stress modulus

stretch modulus

bulk 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).


4

Potential energy is energy that has the potential to be converted into what?

80% Answer Correctly

heat

power

 kinetic energy

work


Solution

Potential energy is the energy of an object by virtue of its position relative to other objects. It is energy that has the potential to be converted into kinetic energy.


5 If the green box weighs 55 lbs. and is 7 ft. from the fulcrum, how much weight would need to be placed at the blue arrow to balance the lever if the arrow's distance from the fulcrum is 8 ft.?
63% Answer Correctly
192.5 lbs.
440 lbs.
48.13 lbs.
96.25 lbs.

Solution

To balance this lever the torques on each side of the fulcrum must be equal. Torque is weight x distance from the fulcrum so the equation for equilibrium is:

Rada = Rbdb

where a represents the left side of the fulcrum and b the right, R is resistance (weight) and d is the distance from the fulcrum.

Solving for Rb, our missing value, and plugging in our variables yields:

Rb = \( \frac{R_ad_a}{d_b} \) = \( \frac{55 lbs. \times 7 ft.}{8 ft.} \) = \( \frac{385 ft⋅lb}{8 ft.} \) = 48.13 lbs.