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A circular disc rotates about its own axis at 200 revolutions per minute. Two particles P and Q on the disc lie at distances of 5 cm and 10 cm from the axis of rotation. What is the ratio of the angular velocities of P and Q?

1. 1:2
2. 1:1
3. 2:1
4. 4:1

Correct answer: 1:1

Solution

All points of a rigid body rotating about a fixed axis share the same angular velocity, so the ratio is 1:1 regardless of distance.

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