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Physics - Rotation Question with Solution | TestHub

PhysicsRotationRotational KinematicsEasy2 minQB

PhysicsEasysingle choice

When a ceiling fan is switched off, its angular velocity reduces to $50 %$ of its initial value while it makes $36$ rotations. If angular retardation of the fan is uniform, then how many more rotations will it make before coming to rest?

Options:

Answer:

Solution:

${(\frac{ω_{0}}{2})}^{2} = ω_{0}^{2} - 2 α θ_{1} \Rightarrow 2 α θ_{1} = \frac{3}{4} ω_{0}^{2}$ ..........(i)

$0 = {(\frac{ω_{0}}{2})}^{2} - 2 α θ_{2} \Rightarrow 2 α θ_{2} = \frac{ω_{0}^{2}}{4}$ .............(ii)

from (i) & (ii) $\frac{θ_{1}}{θ_{2}} = 3$

$\Rightarrow θ_{2} = \frac{θ_{1}}{3} = \frac{36}{3} = 12 r o t a t i o n$

Stream:JEESubject:PhysicsTopic:RotationSubtopic:Rotational Kinematics

⏱ 2mℹ️ Source: QB

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