GCAT Mechanical Reasoning Concepts 4

Question 1

A compound pulley system has 4 rope segments supporting a load. What is the ideal mechanical advantage?

Accepted Answer

4

Answer

The mechanical advantage of a block-and-tackle equals the number of rope segments supporting the moving block.

Question 2

Which material property describes a material's ability to return to its original shape after a deforming force is removed?

Accepted Answer

Elasticity

Answer

Elasticity is the property by which a material recovers its original shape after deformation forces are removed.

Question 3

A flywheel stores kinetic energy in rotation. If its rotational speed doubles, its stored energy:

Accepted Answer

Quadruples

Answer

Rotational kinetic energy = ½Iω²; doubling ω increases energy by 2² = 4 times.

Question 4

In a belt-and-pulley system, a 10 cm driver pulley turns at 600 RPM driving a 30 cm driven pulley. What is the driven pulley's speed?

Accepted Answer

200 RPM

Answer

Pulley speed ratio inversely follows diameter ratio: driven speed = 600 × (10/30) = 200 RPM.

Question 5

A metal beam fixed at one end (cantilever) deflects under a load at its free end. If the load is doubled, the deflection:

Accepted Answer

Doubles

Answer

Beam deflection is directly proportional to load for elastic deformation, so doubling the load doubles deflection.

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