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A thin disc and a thin ring, both have mass M and radius R . Both rotate about axes through their center of mass and are perpendicular to their surfaces at the same angular velocity. Which of the following is true?

Options

  1. AThe ring has higher kinetic energy
  2. BThe disc has higher kinetic energy
  3. CThe ring and the disc have the same kinetic energy
  4. DKinetic energies of both the bodies are zero since they are not in linear motion

Correct answer

A. The ring has higher kinetic energy

Step-by-step solution

kinetic energy of ring is 1 / 2 2 MR2 while that of ring is 1 / 4 2 MR 2 . Hence K .E of ring K .E of disc.

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