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KVPY2012PhysicsRotational Motion

Seven identical coins are rigidly arranged on a flat table in the pattern shown below so that each coin touches its neighbors. Each coin is a thin disc of mass m and radius r . Note that the moment of inertia of an individual coin about an axis passing through centre and perpendicular to the plane of the coin is mr ² / 2 The moment of inertia of the system of seven coins about an axis that passes through the point P

Options

  1. A55 2 mr ²
  2. B127 2 mr ²
  3. C111 2 mr ²
  4. D55 mr ²

Correct answer

C. 111 2 mr ²

Step-by-step solution

By using parallel axis theorem, I = 111 2 mr ²

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