ASVAB Mechanical Comprehension Practice Test 187564 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.07
Score	0%	61%

Review

What is work?

60% Answer Correctly

	The potential for exertion
	Force per unit time
	The movement of an object by a force
	Force per unit distance

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. By definition, work is the displacement of an object resulting from applied force.

2 How much work can a 2 hp engine do in 2 seconds?

52% Answer Correctly

	2200 ft⋅lb
	4 ft⋅lb
	1 ft⋅lb
	8 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:
\( W = 2 hp \times 550 \frac{ft⋅lb}{s} \times 2s = 2200 ft⋅lb \)

When all forces acting on a system cancel each other out, this is called:

80% Answer Correctly

	stasis
	potential energy
	rest
	equilibrium

Solution

When a system is stable or balanced (equilibrium) all forces acting on the system cancel each other out. In the case of torque, equilibrium means that the sum of the anticlockwise moments about a center of rotation equal the sum of the clockwise moments.

The principle of moments defines equilibrium in terms of:

53% Answer Correctly

	speed
	energy
	power
	torque

Solution

According to the principle of moments, you can maintain equilibrium if the moments (forces) tending to clockwise rotation are equal to the moments tending to counterclockwise rotation. Another name for these moments of force is torque.

Two gears are connected and the smaller gear drives the larger gear. The speed of rotation will __________ and the torque will __________.

61% Answer Correctly

	increase, increase
	decrease, decrease
	increase, decrease
	decrease, increase

Solution

Connected gears of different numbers of teeth are used together to change the rotational speed and torque of the input force. If the smaller gear drives the larger gear, the speed of rotation will be reduced and the torque will increase. If the larger gear drives the smaller gear, the speed of rotation will increase and the torque will be reduced.