ASVAB Mechanical Comprehension Practice Test 677205 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.12
Score	0%	62%

Review

1 If the green arrow in this diagram represents 1200 ft⋅lb of work, how far will the box move if it weighs 240 pounds?

73% Answer Correctly

	10 ft.
	0 ft.
	5 ft.
	960 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 1200 ft⋅lb and the resistance force is 240 lbs. and we need to calculate the resistance distance:

W_in = F_resistance x d_resistance
1200 ft⋅lb = 240 lbs. x d_resistance
d_resistance = \( \frac{1200ft⋅lb}{240 lbs.} \) = 5 ft.

Coplanar forces:

62% Answer Correctly

	act in a common plane
	act along the same line of action
	pass through a common point
	have opposite dimensions

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.

The mass of an object correlates to the size of the object but ultimately depends on:

67% Answer Correctly

	gravity
	the object's density
	the object's weight
	the object's potential energy

Solution

Mass is a measure of the amount of matter in an object. In general, larger objects have larger mass than smaller objects but mass ultimately depends on how compact (dense) a substance is.

Which of the following is not true of a first-class lever?

51% Answer Correctly

	increases distance
	decreases distance
	increases force
	changes the direction of force

Solution

A first-class lever is used to increase force or distance while changing the direction of the force. The lever pivots on a fulcrum and, when a force is applied to the lever at one side of the fulcrum, the other end moves in the opposite direction. The position of the fulcrum also defines the mechanical advantage of the lever. If the fulcrum is closer to the force being applied, the load can be moved a greater distance at the expense of requiring a greater input force. If the fulcrum is closer to the load, less force is required but the force must be applied over a longer distance. An example of a first-class lever is a seesaw / teeter-totter.

Which of the following statements about drag is false?

58% Answer Correctly

	drag occurs during movement through a fluid
	slower objects experience more drag than faster objects
	the amount of drag depends on the speed of an object
	the amount of drag depends on the shape of an object

Solution

Drag is friction that opposes movement through a fluid like liquid or air. The amount of drag depends on the shape and speed of the object with slower objects experiencing less drag than faster objects and more aerodynamic objects experiencing less drag than those with a large leading surface area.