A ring, a solid sphere and a thin disc of different masses rotate with same kinetic energy. Equal to

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6.System of Particles and Rotational Motion

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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

D

All will make same number of rotations

Solution

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.

Standard 11

Physics

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