JEE Main 2020PhysicsRotational MotionMediumMCQ

JEE Main 2020 — Rotational Motion Question with Solution

JEE Main 2020 (09 Jan Shift 2)

Question

A uniformly thick wheel with moment of inertia I and radius R is free to rotate about its centre of mass (see fig). A massless string is wrapped over its rim and two blocks of masses m1 and m2m1>m2 are attached to the ends of the string. The system Is released from rest. The angular speed of the wheel when m1 descends by a distance h is:

Choose an option

Show full solutionCorrect option: A
Correct answer
A2m1-m2ghm1+m2R2+I12

Step-by-step explanation

TEi =TEfKi+Ui=Klinear+Krotational+Ufinal
0+0=12m2v2+12m1v2+12Iω2-m1gh+m2gh
2m1-m2ghm1+m2+IR2R2=ω
1R2m1-m2ghm1+m2+IR2

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About this question

This is a previous-year question from JEE Main 2020, covering the Rotational Motion chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.