ASVAB Mechanical Comprehension Practice Test 227836 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.84
Score	0%	57%

Review

1 How much work can a 3 hp engine do in 3 seconds?

52% Answer Correctly

	0 ft⋅lb
	6 ft⋅lb
	4950 ft⋅lb
	1 ft⋅lb

Solution

Horsepower (hp) is a common measure of power output for complex machines. By definition, a 1 hp machine does 550 ft⋅lb of work in 1 second: 1 hp = 550 ft⋅lb/s. Substituting the variables for this problem gives us:
\( W = 3 hp \times 550 \frac{ft⋅lb}{s} \times 3s = 4950 ft⋅lb \)

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

54% Answer Correctly

	higher than
	lower than
	opposite
	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 watt is the unit for which of the following?

71% Answer Correctly

	energy
	work
	power
	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.

What type of load doesn't create specific stress points or vary with time?

60% Answer Correctly

	static uniformly distributed load
	impact load
	concentrated load
	non-uniformly distributed 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.

Which of the following represents the force a surface exerts when an object presses against it?

48% Answer Correctly

	friction
	mass
	normal force
	counter force

Solution

Normal force (F_N) represents the force a surface exerts when an object presses against it.