Question

A disc is rotating freely about its axis. The percentage change in angular velocity of a disc if temperature decreases by 20°C is ______.

(coefficient of linear expansion of material of disc is 5 × 10^-4/°C)

Options

• 1.00

• 2.00

• 3.00

• 4.00

Answer 1

A disc is rotating freely about its axis. The percentage change in angular velocity of a disc if temperature decreases by 20°C is 2.00.

Explanation:

Iω = const.

⇒ `omega ∝ 1/l`

∴ Percentage change in ω = -(% change in I)

= -(2 × Δθ × 100)

= -(2 × 5 × 10^-4 × -20 × 100)

= 2%