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Physics - Rotation Question with Solution | TestHub

PhysicsRotationRotational KinematicsHard2 minPYQ_2019
PhysicsHardsingle choice

A smooth wire of length2πris bent into a circle and kept in a vertical plane. A bead can slide smoothly on the wire. When the circle is rotating with angular speedωabout the vertical diameterAB,as shown in figure, the bead is at rest with respect to the circular ring at positionPas shown. Then the value ofω2is equal to:

Question diagram: A smooth wire of length 2 π r is bent into a circle and kept

Options:

Answer:
C
Solution:


From free body diagram of bead,
Ncos30°=mg.... (1)
Nsin30°=mr2ω2..... (2)
By dividing equation (2) by equation (1)
tan30°=rω22g
ω2=2gr3

Stream:JEESubject:PhysicsTopic:RotationSubtopic:Rotational Kinematics
2mℹ️ Source: PYQ_2019

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