ASVAB Mechanical Comprehension Practice Test 51226 Results

Your Results Global Average
Questions 5 5
Correct 0 2.87
Score 0% 57%

Review

1

What is work?

60% Answer Correctly

The movement of an object by a force

Force per unit time

Force per unit distance

The potential for exertion


Solution

Work is accomplished when force is applied to an object: W = Fd where F is force in newtons (N) and d is distance in meters (m). Thus, the more force that must be applied to move an object, the more work is done and the farther an object is moved by exerting force, the more work is done. By definition, work is the displacement of an object resulting from applied force.


2

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

61% Answer Correctly

low corrosive action

high melting point

chemically stable

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

The work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. This defines which of the following?

60% Answer Correctly

Pascal's law

mechanical advantage

conservation of mechanical energy

work-energy theorem


Solution

The work-energy theorem states that the work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. Simply put, work imparts kinetic energy to the matter upon which the work is being done.


4 If 5 lbs. of force is applied 6 ft. from the fulcrum at the blue arrow and the green box is 3 ft. from the fulcrum, how much would the green box have to weigh to balance the lever?
62% Answer Correctly
5 lbs.
10 lbs.
0 lbs.
30 lbs.

Solution

To balance this lever the torques at the green box and the blue arrow must be equal. Torque is weight x distance from the fulcrum so the equation for equilibrium is:

Rada = Rbdb

where a represents the green box and b the blue arrow, R is resistance (weight/force) and d is the distance from the fulcrum.

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

Ra = \( \frac{R_bd_b}{d_a} \) = \( \frac{5 lbs. \times 6 ft.}{3 ft.} \) = \( \frac{30 ft⋅lb}{3 ft.} \) = 10 lbs.


5

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

total mechanical energy

kinetic energy

potential 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.