ASVAB Mechanical Comprehension Practice Test 668116 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.95
Score	0%	59%

Review

Collinear forces:

72% Answer Correctly

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

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.

2 If the handles of a wheelbarrow are 1.5 ft. from the wheel axle and the load is concentrated at a point 0.5 ft. from the axle, how many pounds of load will a 190 lbs. force lift?

47% Answer Correctly

	570
	63.3
	None of these is correct
	-24.8

Solution

This problem describes a second-class lever and, for a second class lever, the effort force multiplied by the effort distance equals the resistance force multipied by the resistance distance: F_ed_e = F_rd_r. In this problem we're looking for resistance force:
\( F_r = \frac{F_e d_e}{d_r} \)
\( F_r = \frac{190 \times 1.5}{0.5} \)
\( F_r = \frac{285.0}{0.5} \)
\( F_r = 570 \)

Which class of lever is used to increase force on an object in the same direction as the force is applied?

52% Answer Correctly

	second
	first
	all of these
	third

Solution

A second-class lever is used to increase force on an object in the same direction as the force is applied. This lever requires a smaller force to lift a larger load but the force must be applied over a greater distance. The fulcrum is placed at one end of the lever and mechanical advantage increases as the object being lifted is moved closer to the fulcrum or the length of the lever is increased. An example of a second-class lever is a wheelbarrow.

A wedge converts force applied to its blunt end into force __________ its inclined surface.

57% Answer Correctly

	opposite to
	perpendicular to
	along
	parallel to

Solution

The wedge is a moving inclined plane that is used to lift, hold, or break apart an object. A wedge converts force applied to its blunt end into force perpendicular to its inclined surface. In contrast to a stationary plane where force is applied to the object being moved, with a wedge the object is stationary and the force is being applied to the plane. Examples of a wedge include knives and chisels.

What type of load varies with time or affects a structure that experiences a high degree of movement?

66% Answer Correctly

	impact load
	concentrated load
	static load
	dynamic 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.