ASVAB Mechanical Comprehension Practice Test 161111 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.06
Score	0%	61%

Review

1 If the green arrow in this diagram represents 450 ft⋅lb of work, how far will the box move if it weighs 150 pounds?

72% Answer Correctly

	75 ft.
	600 ft.
	6 ft.
	3 ft.

Solution

The Law of Work states that the work put into a machine is equal to the work received from the machine under ideal conditions. In equation form, that's:

W_in = W_out
F_effort x d_effort = F_resistance x d_resistance

In this problem, the effort work is 450 ft⋅lb and the resistance force is 150 lbs. and we need to calculate the resistance distance:

W_in = F_resistance x d_resistance
450 ft⋅lb = 150 lbs. x d_resistance
d_resistance = \( \frac{450ft⋅lb}{150 lbs.} \) = 3 ft.

Which of the following is not a modulus of elasticity?

47% Answer Correctly

	bulk modulus
	shear modulus
	stress modulus
	stretch 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).

For a hydraulic system, pressure applied to the input of the system will increase the pressure in which parts of the system?

58% Answer Correctly

	the portions of the system at an altitude below the input
	all of these are correct
	the portions of the system at an altitude above the input
	everywhere in the system

Solution

Pascal's law states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere. For a hydraulic system, this means that a pressure applied to the input of the system will increase the pressure everywhere in the system.

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

57% Answer Correctly

	input gear
	idler gear
	driver gear
	driven 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.

Collinear forces:

72% Answer Correctly

	act along the same line of action
	pass through a common point
	are unrelated to each other
	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.