Question

If polar ice caps melt, then the angular velocity of rotation of earth:

• A. increases
• B. decreases
• C. remains constant
• D. depends on when the ice melts.

Answer 1

Answer: (B)

decreases

No external torque.
$\therefore$ Angular Momentum will remain conserved.
$\therefore L_1=L_2$
$\therefore I_1{\omega }_1=I_2{\omega }_2$
If polar ice melts, then mass will move into the oceans due the which moment of inertia $l$ will increase, which results in decrease in the angular velocity.