ASVAB Mechanical Comprehension Practice Test 835032 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.58
Score	0%	72%

Review

Which of the following is the formula for hydraulic pressure?

58% Answer Correctly

	P = FA²
	P = FA
	P = F/A
	P = F/A²

Solution

Hydraulics is the transmission of force through the use of liquids. Liquids are especially suited for transferring force in complex machines because they compress very little and can occupy very small spaces. Hydraulic pressure is calculated by dividing force by the area over which it is applied: P = F/A where F is force in pounds, A is area in square inches, and the resulting pressure is in pounds per square inch (psi).

Which of the following is the formula for gravitational potential energy?

61% Answer Correctly

	\(PE = { 1 \over 2} mg^2\)
	\(PE = mg^2h\)
	\(PE = mgh\)
	\(PE = { 1 \over 2} mv^2\)

Solution

Gravitational potential energy is energy by virtue of gravity. The higher an object is raised above a surface the greater the distance it must fall to reach that surface and the more velocity it will build as it falls. For gravitational potential energy, PE = mgh where m is mass (kilograms), h is height (meters), and g is acceleration due to gravity which is a constant (9.8 m/s²).

The steering wheel of a car is an example of which type of simple machine?

89% Answer Correctly

	fixed pulley
	wheel and axle
	block and tackle
	first-class lever

Solution

A wheel and axle uses two different diameter wheels mounted to a connecting axle. Force is applied to the larger wheel and large movements of this wheel result in small movements in the smaller wheel. Because a larger movement distance is being translated to a smaller distance, force is increased with a mechanical advantage equal to the ratio of the diameters of the wheels. An example of a wheel and axle is the steering wheel of a car.

4 If input effort is 400 ft⋅lb, what output effort will be produced by a machine with a mechanical advantage of 2?

79% Answer Correctly

	1600ft⋅lb
	400ft⋅lb
	800 ft⋅lb
	0ft⋅lb

Solution

Mechanical advantage is the ratio of output force to input force and tells us by how many times a machine multiplies input effort. So, a machine with a mechanical advantage of 2 will multiply an input effort of 400 ft⋅lb by 2 to produce an output effort of 800 ft⋅lb.

The standard unit of energy is the:

73% Answer Correctly

	Volt
	Watt
	Horsepower
	Joule

Solution

The Joule (J) is the standard unit of energy and has the unit \({kg \times m^2} \over s^2\).