ASVAB Mechanical Comprehension Practice Test 146690 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.80
Score	0%	56%

Review

Force of friction due to kinetic friction is __________ the force of friction due to static friction.

40% Answer Correctly

	the same as
	lower than
	higher than
	opposite

Solution

The formula for force of friction (F_f) is the same whether kinetic or static friction applies: F_{f =}μF_N. To distinguish between kinetic and static friction, μ_k and μ_s are often used in place of μ.

A watt is the unit for which of the following?

71% Answer Correctly

	work
	power
	energy
	mechanical advantage

Solution

Power is the rate at which work is done, P = w/t, or work per unit time. The watt (W) is the unit for power and is equal to 1 joule (or newton-meter) per second. Horsepower (hp) is another familiar unit of power used primarily for rating internal combustion engines. 1 hp equals 746 watts.

3 If A = 4 ft. and the green box weighs 5 lbs. what is the torque acting on the A side of this lever?

75% Answer Correctly

	1 ft⋅lb
	20 ft⋅lb
	10 ft⋅lb
	6 ft⋅lb

Solution

For a lever, torque is weight x distance from the fulcrum which, in this case, is: 5 ft. x 4 lbs. = 20 ft⋅lb

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

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

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.

The principle of conservation of mechanical energy states that, as long as no other forces are applied, what will remain constant as an object falls?

45% Answer Correctly

	acceleration
	potential energy
	kinetic energy
	total mechanical energy

Solution

As an object falls, its potential energy is converted into kinetic energy. The principle of conservation of mechanical energy states that, as long as no other forces are applied, total mechanical energy (PE + KE) of the object will remain constant at all points in its descent.