ASVAB Mechanical Comprehension Practice Test 174349 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.25
Score	0%	65%

Review

Sam can do 50 ft. lb. of work in 2 minutes and 5 seconds. What would Sam have to do to increase his power output?

64% Answer Correctly

	do 100 ft. lb. of work in 4 minutes 12 seconds
	do the work in 3 minutes
	do the work in 2 minutes
	do 25 ft. lb. of work in 2 minutes 5 seconds

Solution

Power is the rate of doing work or \(\frac{W}{t}\). To increase power, increase the work being done in the same amount of time or do the same amount of work in less time.

Which of the following will increase the mechanical advantage of this inclined plane?

59% Answer Correctly

	increase the force acting at the blue arrow
	shorten the ramp
	lengthen the ramp
	lower the force acting at the blue arrow

Solution

The mechanical advantage (MA) of an inclined plane is the effort distance divided by the resistance distance. In order to increase mechanical advantage, this ratio must increase which means making the effort distance longer and this can be accomplished by lengthening the length of the ramp.

Which of the following is not a characteristic of a ceramic?

61% Answer Correctly

	low density
	low corrosive action
	high melting point
	chemically stable

Solution

Ceramics are mixtures of metallic and nonmetallic elements that withstand exteme thermal, chemical, and pressure environments. They have a high melting point, low corrosive action, and are chemically stable. Examples include rock, sand, clay, glass, brick, and porcelain.

4 What is the mechanical advantage of this inclined plane if the length of the ramp is 21 ft. and the height of the green box is 3 ft.?

82% Answer Correctly

	7
	21
	12
	10

Solution

The mechanical advantage (MA) of an inclined plane is the effort distance divided by the resistance distance. In this case, the effort distance is the length of the ramp and the resistance distance is the height of the green box:

MA = \( \frac{d_e}{d_r} \) = \( \frac{21 ft.}{3 ft.} \) = 7

Which of the following is the formula for gravitational potential energy?

61% Answer Correctly

	\(PE = { 1 \over 2} mg^2\)
	\(PE = mgh\)
	\(PE = mg^2h\)
	\(PE = { 1 \over 2} mv^2\)

Solution

Gravitational potential energy is energy by virtue of gravity. The higher an object is raised above a surface the greater the distance it must fall to reach that surface and the more velocity it will build as it falls. For gravitational potential energy, PE = mgh where m is mass (kilograms), h is height (meters), and g is acceleration due to gravity which is a constant (9.8 m/s²).