Question

A uniform metallic rod rotates about its perpendicular bisector with constant angular speed. If it is heated uniformly to raise its temperature to a certain value, its speed of rotation ______.

Options

• remains constant

• may increase or decrease depending on density of metal

• increases

• decreases

Answer 1

A uniform metallic rod rotates about its perpendicular bisector with constant angular speed. If it is heated uniformly to raise its temperature to a certain value, its speed of rotation decreases.

Explanation:

When temperature is increased, length will increase

I₁ω₁ = I₂ω₂

`"mL"_1^2/12 omega_12="mL"_2^2/12 omega_2`

Since L₂ > L₁

∴ ω₂ < ω₁