ASVAB Mechanical Comprehension 2

Question 1

A hydraulic jack uses a small piston with area 2 sq in and a large piston with area 20 sq in. If you apply 50 lbs to the small piston, what force does the large piston exert?

Accepted Answer

500 lbs

Answer

Pascal's law: force scales with area ratio, so 50 × (20/2) = 500 lbs.

Question 2

Which type of gear arrangement reverses the direction of rotation between the input and output shaft?

Accepted Answer

Two meshing spur gears

Answer

Two meshing spur gears always rotate in opposite directions.

Question 3

A spring with a spring constant of 200 N/m is compressed 0.05 m. How much potential energy is stored?

Accepted Answer

0.25 J

Answer

Spring potential energy = ½kx² = ½ × 200 × 0.05² = 0.25 J.

Question 4

A solid steel cylinder and a hollow steel cylinder of the same outer diameter and length are both rolled down an incline. Which reaches the bottom first?

Accepted Answer

The solid cylinder

Answer

The solid cylinder has a lower moment of inertia relative to its mass, so it accelerates faster down the incline.

Question 5

What is the mechanical advantage of a single fixed pulley?

Accepted Answer

1

Answer

A single fixed pulley only changes the direction of force and provides a mechanical advantage of 1.

ASVAB - Armed Services Vocational Aptitude Battery Practice Test

ASVAB - Armed Services Vocational Aptitude Battery Practice Test

ASVAB Mechanical Comprehension 2