ASVAB Mechanical Comprehension Practice Test 359623 Results

	Your Results	Global Average
Questions	5	5
Correct	0	2.78
Score	0%	56%

Review

The advantage of using a third-class lever is that it increases:

37% Answer Correctly

	the force applied to the load
	the mechanical advantage of the lever
	the distance traveled by the load
	the speed of the load

Solution

A third-class lever is used to increase distance traveled by an object in the same direction as the force applied. The fulcrum is at one end of the lever, the object at the other, and the force is applied between them. This lever does not impart a mechanical advantage as the effort force must be greater than the load but does impart extra speed to the load. Examples of third-class levers are shovels and tweezers.

2 What is the power output of a 1 hp engine that's 45% efficient?

40% Answer Correctly

	45 \( \frac{ft⋅lb}{s} \)
	247.5 \( \frac{ft⋅lb}{s} \)
	0 \( \frac{ft⋅lb}{s} \)
	990 \( \frac{ft⋅lb}{s} \)

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 1 hp x 550 \( \frac{ft⋅lb}{s} \) = 550 \( \frac{ft⋅lb}{s} \)
\( P_{o} = \frac{E \times P_{i}}{100} = \frac{45 \times 550 \frac{ft⋅lb}{s}}{100} \) \( = \frac{24750 \frac{ft⋅lb}{s}}{100} \) = 247.5 \( \frac{ft⋅lb}{s} \)

What type of load creates different stresses at different locations on a structure?

60% Answer Correctly

	impact load
	dynamic load
	static uniformly distributed load
	non-uniformly distributed load

Solution

A concentrated load acts on a relatively small area of a structure, a static uniformly distributed load doesn't create specific stress points or vary with time, a dynamic load varies with time or affects a structure that experiences a high degree of movement, an impact load is sudden and for a relatively short duration and a non-uniformly distributed load creates different stresses at different locations on a structure.

Which of the following statements about drag is false?

58% Answer Correctly

	the amount of drag depends on the speed of an object
	slower objects experience more drag than faster objects
	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.

5 What is the mechanical advantage of this inclined plane if the length of the ramp is 63 ft. and the height of the green box is 9 ft.?

82% Answer Correctly

	10
	3
	7
	14

Solution

The mechanical advantage (MA) of an inclined plane is the effort distance divided by the resistance distance. In this case, the effort distance is the length of the ramp and the resistance distance is the height of the green box:

MA = \( \frac{d_e}{d_r} \) = \( \frac{63 ft.}{9 ft.} \) = 7