ASVAB Mechanical Comprehension Practice Test 403288 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.93
Score	0%	59%

Review

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

70% Answer Correctly

	weight
	density
	mass
	potential energy

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.

Which of the following statements about drag is false?

58% Answer Correctly

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

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.

3 What is the power output of a 3 hp engine that's 80% efficient?

40% Answer Correctly

	5280 \( \frac{ft⋅lb}{s} \)
	26 \( \frac{ft⋅lb}{s} \)
	1320 \( \frac{ft⋅lb}{s} \)
	330 \( \frac{ft⋅lb}{s} \)

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 3 hp x 550 \( \frac{ft⋅lb}{s} \) = 1650 \( \frac{ft⋅lb}{s} \)
\( P_{o} = \frac{E \times P_{i}}{100} = \frac{80 \times 1650 \frac{ft⋅lb}{s}}{100} \) \( = \frac{132000 \frac{ft⋅lb}{s}}{100} \) = 1320 \( \frac{ft⋅lb}{s} \)

The work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. This defines which of the following?

60% Answer Correctly

	work-energy theorem
	conservation of mechanical energy
	Pascal's law
	mechanical advantage

Solution

The work-energy theorem states that the work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. Simply put, work imparts kinetic energy to the matter upon which the work is being done.

Which of the following will increase the mechanical advantage of this inclined plane?

59% Answer Correctly

	lower the force acting at the blue arrow
	shorten the ramp
	increase the force acting at the blue arrow
	lengthen the ramp

Solution

The mechanical advantage (MA) of an inclined plane is the effort distance divided by the resistance distance. In order to increase mechanical advantage, this ratio must increase which means making the effort distance longer and this can be accomplished by lengthening the length of the ramp.