ASVAB Mechanical Comprehension Practice Test 547844 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.06
Score	0%	61%

Review

Tension is a force that does which of the following?

75% Answer Correctly

	stretches an object
	slows an object
	heats up an object
	compacts an object

Solution

Tension is a force that stretches or elongates something. When a cable or rope is used to pull an object, for example, it stretches internally as it accepts the weight that it's moving. Although tension is often treated as applying equally to all parts of a material, it's greater at the places where the material is under the most stress.

The force exerted on an object due to gravity is called:

70% Answer Correctly

	potential energy
	mass
	weight
	density

Solution

Mass is an intrinsic property of matter and does not vary. Weight is the force exerted on the mass of an object due to gravity and a specific case of Newton's Second Law of Motion. Replace force with weight and acceleration with acceleration due to gravity on Earth (g) and the result is the formula for weight: W = mg or, substituting for g, weight equals mass multiplied by 9.8 m/s².

The mechanical advantage of a third class lever is always:

37% Answer Correctly

	equal to one
	less than one
	not equal to one
	greater than one

Solution

A third class lever is designed to multiply distance and speed at the expense of effort force. Because the effort force is greater than the resistance, the mechanical advantage of a third class lever is always less than one.

An example of a third class lever is a broom. The fulcrum is at your hand on the end of the broom, the effort force is your other hand in the middle, and the resistance is at the bottom bristles. The effort force of your hand in the middle multiplies the distance and speed of the bristles at the bottom but at the expense of producing a brushing force that's less than the force you're applying with your hand.

4 How much work can a 8 hp engine do in 9 seconds?

52% Answer Correctly

	39600 ft⋅lb
	4 ft⋅lb
	32 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:
\( W = 8 hp \times 550 \frac{ft⋅lb}{s} \times 9s = 39600 ft⋅lb \)

When it comes to force, mass and acceleration have what kind of relationship?

66% Answer Correctly

	logarithmic
	inverse
	linear
	exponential

Solution

Newton's Second Law of Motion states that "The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object." This Law describes the linear relationship between mass and acceleration when it comes to force and leads to the formula F = ma or force equals mass multiplied by rate of acceleration.