ASVAB Mechanical Comprehension Principles Flashcards

A hydraulic jack has an input piston with area 2 sq in and an output piston with area 20 sq in. If you apply 50 lbs of force to the input, what force is produced at the output?

Answer: 500 lbs

Pascal's law: output force = input force × (output area / input area) = 50 × (20/2) = 500 lbs.

Which type of gear arrangement reverses the direction of rotation between the driver and driven gear?

Answer: Spur gear pair (external)

Two external spur gears meshed together rotate in opposite directions.

A steel beam is supported at both ends and loaded in the center. Where does the maximum bending stress occur?

Answer: At the center top and bottom surfaces

Maximum bending stress occurs at the outermost fibers (top and bottom) at the point of maximum bending moment.

A flywheel is used in an engine primarily to:

Answer: Store rotational energy and smooth out power pulses

A flywheel's rotational inertia stores energy during power strokes and releases it during non-power strokes, smoothing engine output.

If a 10-foot ladder leans against a wall with its base 6 feet from the wall, how high up the wall does it reach?

Answer: 8 feet

Using the Pythagorean theorem: height = √(10² - 6²) = √(100-36) = √64 = 8 feet.

What happens to the pressure of a gas in a sealed container when the temperature increases (volume constant)?

Answer: Pressure increases

Gay-Lussac's Law states that at constant volume, pressure is directly proportional to absolute temperature.

A cam converts:

Answer: Rotary motion to linear (reciprocating) motion

A cam is a rotating or sliding piece that converts rotary motion into linear reciprocating motion via a follower.