MCQ
A ring, a solid sphere and a thin disc of different masses rotate with the same kinetic energy. Equal torques are applied to stop them. Which will make the least number of rotations before coming to rest
  • A
    Disc
  • B
    Ring
  • C
    Solid sphere
  • All will make same number of rotations

Answer

Correct option: D.
All will make same number of rotations
d
As $W = \tau \theta $ = Energy

$⇒$ $\theta  = \frac{{{\rm{Energy}}}}{\tau } = 2n\pi $

So, if energy and torque are same then all the bodies will make same number of rotation.

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