Question:
A circular disc is rotating with angular velocity \(\omega\). If a man standing at the edge of the disc walks towards its centre then the angular velocity of the disc will
A circular disc is rotating with angular velocity \(\omega\). If a man standing at the edge of the disc walks towards its centre then the angular velocity of the disc will
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This is similar to a spinning ice skater pulling arms inward to spin faster.
Updated On: Apr 23, 2026
- decrease
- increase
- be halved
- not change
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Verified By Collegedunia
The Correct Option is B
Solution and Explanation
Step 1: Understanding the Concept:
Angular momentum is conserved when no external torque acts. \(L = I\omega = \text{constant}\).
Step 2: Detailed Explanation:
When man walks from edge to centre, moment of inertia \(I\) decreases (mass moves closer to axis).
Since \(L = I\omega\) is constant, if \(I\) decreases, \(\omega\) must increase.
Step 3: Final Answer:
Thus, angular velocity increases.
Angular momentum is conserved when no external torque acts. \(L = I\omega = \text{constant}\).
Step 2: Detailed Explanation:
When man walks from edge to centre, moment of inertia \(I\) decreases (mass moves closer to axis).
Since \(L = I\omega\) is constant, if \(I\) decreases, \(\omega\) must increase.
Step 3: Final Answer:
Thus, angular velocity increases.
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