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Most Important Selected Qs for JEE AdvancedPhysicsRotational Motion

Paragraph: Greek lores have a fable of Sisyphus, a celebrated philosopher. He was punished in Hades for rebelling against the king. The punishment was to roll a spherical stone up a hill from where it would invariably roll down to the other side. He would run after the stone, to catch it back and roll it back uphill. The top of the hill was always a position of unstable equilibrium. The sphere and Sisyphus have same

Options

  1. Afriction on Sisyphus would be backwards and equal to that on sphere
  2. Bfriction on Sisyphus would be forwards and greater than on sphere
  3. Cfriction on Sisyphus would be backwards and less than on sphere
  4. Dfriction on Sisyphus would be forwards and equal to that on sphere

Correct answer

A. friction on Sisyphus would be backwards and equal to that on sphere

Step-by-step solution

aligned & F _ F at R , =0, a =0 & mg + F = f ₁ sisyphus & F + f ₂= mg stone & FR = f ₂ R Stone & F = f ₂ ~F = mg 2 = f ₂ mg & array l / 2 array & for sisyphus, & array l mgsin F = f ₁ mg 3 mg 2 mg array 3 / 2 aligned For stone to roll as well as sisyphus to not slip 3 / 2 .

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