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NTA Abhyas JEE Main2020PhysicsRotational MotionPractice

Two particles of masses m and 2 m are attached to the massless rod of length 2 l as shown in figure. The rod is hinged at its midpoint O and is free to rotate in vertical plane about hinge. The minimum speed v at the given instant so that it can complete the circle.

Options

  1. Ag l
  2. B4 g l
  3. C5 g l
  4. D4 g l 3

Correct answer

D. 4 g l 3

Step-by-step solution

W g = K f - K i m g 2 l - 2 m g 2 l = 0 - 1 2 m v 2 + 1 2 2 m v 2 - 2 m g l = - 3 2 m v 2 v = 4 g l 3

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