ASVAB Mechanical Comprehension Practice Test 686760 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.48
Score	0%	70%

Review

For any given surface, the coefficient of static friction is ___________ the coefficient of kinetic friction.

54% Answer Correctly

	opposite
	lower than
	higher than
	equal to

Solution

For any given surface, the coefficient of static friction is higher than the coefficient of kinetic friction. More force is required to initally get an object moving than is required to keep it moving. Additionally, static friction only arises in response to an attempt to move an object (overcome the normal force between it and the surface).

A fixed pulley has a mechanical advantage of:

68% Answer Correctly

	1
	0
	2
	-1

Solution

A fixed pulley is used to change the direction of a force and does not multiply the force applied. As such, it has a mechanical advantage of one. The benefit of a fixed pulley is that it can allow the force to be applied at a more convenient angle, for example, pulling downward or horizontally to lift an object instead of upward.

Tension is a force that does which of the following?

75% Answer Correctly

	slows an object
	stretches an object
	heats up an object
	compacts an object

Solution

Tension is a force that stretches or elongates something. When a cable or rope is used to pull an object, for example, it stretches internally as it accepts the weight that it's moving. Although tension is often treated as applying equally to all parts of a material, it's greater at the places where the material is under the most stress.

4 If input effort is 700 ft⋅lb, what output effort will be produced by a machine with a mechanical advantage of 9?

79% Answer Correctly

	6300 ft⋅lb
	25200ft⋅lb
	0ft⋅lb
	12600ft⋅lb

Solution

Mechanical advantage is the ratio of output force to input force and tells us by how many times a machine multiplies input effort. So, a machine with a mechanical advantage of 9 will multiply an input effort of 700 ft⋅lb by 9 to produce an output effort of 6300 ft⋅lb.

Friction between two or more solid objects that are not moving relative to each other is called:

73% Answer Correctly

	kinetic friction
	dynamic friction
	static friction
	gravitational friction

Solution

Static friction is friction between two or more solid objects that are not moving relative to each other. An example is the friction that prevents a box on a sloped surface from sliding farther down the surface.