Question

A rigid spherical body is spinning around an axis without any external torque. Due to rise of temperature its volume increases by 3% . Then percentage change in its angular speed is

• A. -2
• B. -1
• C. -3
• D. 1

Answer 1

Answer: (A)

-2

Answer 2

Volume increases by 3% means, its radius increases by 1% Therefore I increases and $\omega$ decreases $\omega \,\propto\,\frac{1}{I}\Rightarrow\,\propto\,\frac{1}{R^2}$ $\therefore \,change\,in\,\omega\,is\,-2$