ASVAB Mechanical Comprehension Test 4

Question 1

A boat propeller converts engine torque into thrust. If the pitch of the propeller increases while RPM stays the same, what happens?

Accepted Answer

The boat moves farther per revolution but requires more torque

Answer

Higher pitch means more water moved per revolution, increasing thrust potential but also requiring more torque from the engine.

Question 2

A pipe narrows from a diameter of 4 cm to 2 cm. If water flows at 1 m/s in the wide section, what is the speed in the narrow section?

Accepted Answer

4 m/s

Answer

By continuity (A₁v₁ = A₂v₂), area decreases by factor 4 (radius halved), so speed increases 4×: 1 × 4 = 4 m/s.

Question 3

A lever is used to lift a 300-lb rock. The rock is 2 feet from the fulcrum and effort is applied 6 feet from the fulcrum. How much effort force is needed?

Accepted Answer

100 lbs

Answer

By the lever principle: effort × 6 = 300 × 2, so effort = 600/6 = 100 lbs.

Question 4

Which material property describes a material's ability to be drawn into a wire without breaking?

Accepted Answer

Ductility

Answer

Ductility is the property that allows a material to be stretched into thin wires under tensile stress.

Question 5

Two blocks are connected by a rope over a frictionless pulley. Block A (10 kg) is on a frictionless surface; Block B (5 kg) hangs vertically. What happens when released?

Accepted Answer

Block A slides toward the pulley as Block B falls

Answer

Block B's weight pulls the rope, accelerating Block A horizontally toward the pulley while Block B descends.

ASVAB - Armed Services Vocational Aptitude Battery Practice Test

ASVAB - Armed Services Vocational Aptitude Battery Practice Test

ASVAB Mechanical Comprehension Test 4