A uniformly thick wheel with moment of inertia I and radius R is free to rotate about its centre of mass…

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:

  1. 2m1-m2ghm1+m2R2+I12
  2. 2m1+m2ghm1+m2R2+I12
  3. m1-m2m1+m2R2+112gh
  4. m1+m2m1+m2R2+I12gh

Solution

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

Asked in: JEE Main 2020 (09 Jan Shift 2)

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