ASVAB Mechanical Comprehension Practice Test 877906 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.97
Score	0%	59%

Review

Lisa lifts a 25 pound box from the floor onto a loading dock 4 ft. off the ground. Sam slides the same box along a ramp to move it up another 4 ft. onto a flatbed truck. Who has done more work?

50% Answer Correctly

	Sam
	Neither have done any work
	They have done an equal amount of work
	Lisa

Solution

Work is force multiplied by distance. Because both Connie and Sam moved the same weight the same distance they have done an equal amount of work. Sam employed the mechnacial advantage of an inclined plane so he exerted less effort to do the work but the amount of work done was still the same.

Coplanar forces:

62% Answer Correctly

	have opposite dimensions
	act along the same line of action
	act in a common plane
	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.

Concurrent forces:

55% Answer Correctly

	act along the same line of action
	act in a common plane
	act in a common dimension
	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.

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

52% Answer Correctly

	all of these
	first
	third
	second

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 block and tackle with four pulleys would have a mechanical advantage of:

79% Answer Correctly

	0
	2
	4
	1

Solution

Two or more pulleys used together constitute a block and tackle which, unlike a fixed pulley, does impart mechanical advantage as a function of the number of pulleys that make up the arrangement. So, for example, a block and tackle with three pulleys would have a mechanical advantage of three.