ASVAB Mechanical Comprehension Practice Test 559235 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.81
Score	0%	56%

Review

1 How much work can a 5 hp engine do in 3 seconds?

52% Answer Correctly

	8250 ft⋅lb
	1 ft⋅lb
	20 ft⋅lb
	2 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:
\( W = 5 hp \times 550 \frac{ft⋅lb}{s} \times 3s = 8250 ft⋅lb \)

Depending on where you apply effort and resistance, the wheel and axle can multiply:

45% Answer Correctly

	speed or power
	power or distance
	force or speed
	force or distance

Solution

If you apply the resistance to the axle and the effort to the wheel, the wheel and axle will multiply force and if you apply the resistance to the wheel and the effort to the axle, it will multiply speed.

Which of the following statements about drag is false?

58% Answer Correctly

	the amount of drag depends on the shape of an object
	slower objects experience more drag than faster objects
	drag occurs during movement through a fluid
	the amount of drag depends on the speed of an object

Solution

Drag is friction that opposes movement through a fluid like liquid or air. The amount of drag depends on the shape and speed of the object with slower objects experiencing less drag than faster objects and more aerodynamic objects experiencing less drag than those with a large leading surface area.

Connected gears of different numbers of teeth are used together to change which of the following charasteristics of the input force?

65% Answer Correctly

	force
	energy
	rotational direction
	torque

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.

An inclined plane increases ___________ to reduce ____________.

58% Answer Correctly

	distance, power
	force, power
	force, distance
	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.