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KVPY2017PhysicsRotational Motion

A small ring is rolling without slipping on the circumference of a large bowl as shown in the figure. The ring is moving down at P ₁ , comes down to the lower most point P ₂ and is climbing up at P ₃ . Let v _ C M denote the velocity of the centre of mass of the ring. Choose the correct statement regarding the frictional force on the ring.

Options

  1. AIt is opposite to v _ CM at the points P ₁, P ₂ and P ₃
  2. BIt is opposite to v _ C M at P₁ and in the same direction as v _ CM at P ₃
  3. CIt is in the same direction as v _ C M at P₁ and opposite to v _ C M at P₃
  4. DIt is zero at the points P ₁, P ₂ and P ₃

Correct answer

B. It is opposite to v _ C M at P₁ and in the same direction as v _ CM at P ₃

Step-by-step solution

fr ₁ will increase . fr ₃ will decrease .

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