Physics - Rotation Question with Solution | TestHub

PhysicsRotationTorque / angular accelerationEasy2 minPYQ_2019

PhysicsEasysingle choice

A stationary horizontal disc is free to rotate about its axis. When a torque is applied on it, its kinetic energy as a function of $θ$ , where $θ$ is the angle by which it has rotated, is given as $k θ^{2}$ . If its moment of inertia is $I$ then the angular acceleration of the disc is:

Options:

Answer:

Solution:

Kinetic Energy $= k θ^{2}$
$\frac{1}{2} I ω^{2} = k θ^{2}$
$ω^{2} = \frac{2 k θ^{2}}{I}$
Differentiate both side w.r.t. $θ$ .
$2 ω \frac{d ω}{d θ} = \frac{4 k θ}{I}$
$ω \frac{d ω}{d θ} = \frac{2 k θ}{I}$
$α = \frac{2 k θ}{I}$

Stream:JEESubject:PhysicsTopic:RotationSubtopic:Torque / angular acceleration

⏱ 2mℹ️ Source: PYQ_2019

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