ASVAB Mechanical Comprehension Practice Test 959894 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.67
Score	0%	53%

Review

1 What is the power output of a 4 hp engine that's 55% efficient?

40% Answer Correctly

	13 \( \frac{ft⋅lb}{s} \)
	1210 \( \frac{ft⋅lb}{s} \)
	302.5 \( \frac{ft⋅lb}{s} \)
	2420 \( \frac{ft⋅lb}{s} \)

Solution

\( Efficiency = \frac{Power_{out}}{Power_{in}} \times 100 \)
Solving for power out: \( P_{o} = \frac{E \times P_{i}}{100} \)
Knowing that 1 hp = 550 \( \frac{ft⋅lb}{s} \), P_i becomes 4 hp x 550 \( \frac{ft⋅lb}{s} \) = 2200 \( \frac{ft⋅lb}{s} \)
\( P_{o} = \frac{E \times P_{i}}{100} = \frac{55 \times 2200 \frac{ft⋅lb}{s}}{100} \) \( = \frac{121000 \frac{ft⋅lb}{s}}{100} \) = 1210 \( \frac{ft⋅lb}{s} \)

Potential energy is energy that has the potential to be converted into what?

81% Answer Correctly

	kinetic energy
	work
	power
	heat

Solution

Potential energy is the energy of an object by virtue of its position relative to other objects. It is energy that has the potential to be converted into kinetic energy.

An inclined plane increases ___________ to reduce ____________.

59% Answer Correctly

	force, distance
	force, power
	distance, power
	distance, force

Solution

An inclined plane is a simple machine that reduces the force needed to raise an object to a certain height. Work equals force x distance and, by increasing the distance that the object travels, an inclined plane reduces the force necessary to raise it to a particular height. In this case, the mechanical advantage is to make the task easier. An example of an inclined plane is a ramp.

What's the last gear in a gear train called?

38% Answer Correctly

	output gear
	driven gear
	driver gear
	idler gear

Solution

A gear train is two or more gears linked together. Gear trains are designed to increase or reduce the speed or torque outpout of a rotating system or change the direction of its output. The first gear in the chain is called the driver and the last gear in the chain the driven gear with the gears between them called idler gears.

Assuming force applied remains constant, which of the following will result in more work being done?

53% Answer Correctly

	moving the object with more acceleration
	moving the object farther
	moving the object with more speed
	increasing the coefficient of friction

Solution

Work is accomplished when force is applied to an object: W = Fd where F is force in newtons (N) and d is distance in meters (m). Thus, the more force that must be applied to move an object, the more work is done and the farther an object is moved by exerting force, the more work is done.