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Physics - Rotation Question with Solution | TestHub

PhysicsRotationAngular momentumMedium2 minPYQ_2020

PhysicsMediumsingle choice

A rotating body has angular momentum 'L'. If its frequency of rotation is halved and rotational kinetic energy is doubled, its angular momentum becomes

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Kinetic energy $k = \frac{1}{2} I ω^{2}$ $∴ \frac{k _{2}}{k _{1}} = \frac{I _{2} w _{2}^{2}}{I _{1} ω _{1}^{2}}$ $∴ 2 = \frac{I _{2}}{I _{1}} (\frac{l}{2})^{2} ∴ \frac{I _{2}}{I _{1}} = 8$ Angular momentum $L = I ω$ $\frac{L _{2}}{L _{1}} = \frac{I _{2} ω _{2}}{I _{1} ω _{1}} = 8 \times \frac{1}{2} = 4$ $∴ L_{2} = 4 L_{1} = 4 L$

Stream:MHT_CETSubject:PhysicsTopic:RotationSubtopic:Angular momentum

⏱ 2mℹ️ Source: PYQ_2020

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