GCAT Mechanical Reasoning Concepts 2

Question 1

A hydraulic press has an input piston with area 2 cm² and an output piston with area 20 cm². If you apply 50 N to the input, what force does the output produce?

Accepted Answer

500 N

Answer

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

Question 2

Two gears mesh together. Gear A has 10 teeth and Gear B has 40 teeth. If Gear A rotates at 200 RPM, how fast does Gear B rotate?

Accepted Answer

50 RPM

Answer

Gear speed ratio is inverse to tooth ratio: Gear B = 200 × (10/40) = 50 RPM.

Question 3

A block rests on a ramp inclined at 30°. Compared to lifting it straight up, the ramp requires approximately how much force (ignoring friction)?

Accepted Answer

Half the force

Answer

An inclined plane reduces required force by sin(angle); sin(30°) = 0.5, so half the force is needed.

Question 4

Water flows through a pipe that narrows from a 4-inch diameter to a 2-inch diameter. What happens to the water's velocity in the narrow section?

Accepted Answer

It quadruples

Answer

By the continuity equation, velocity × cross-sectional area is constant; area drops by factor 4, so velocity quadruples.

Question 5

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

Accepted Answer

0.25 J

Answer

Elastic PE = ½kx² = ½ × 200 × (0.05)² = 0.25 J.

GCAT - General Cognitive Ability Test Practice Test

GCAT - General Cognitive Ability Test Practice Test

GCAT Mechanical Reasoning Concepts 2