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A rod AB of length L and mass M is free to move on a frictionless horizontal surface. It is moving with a velocity v , as shown in figure. End B of rod AB strikes the end of the wall. Assuming elastic impact, the angular velocity of the rod AB , just after impact, is

Options

  1. Av 2 L
  2. B3 v L
  3. C3 v 2 L
  4. Dv L

Correct answer

B. 3 v L

Step-by-step solution

From the conservation of angular momentum, ⇒ M v c m L 2 + M L 2 12 ω = M v L 2 ⇒ v c m + ω L 6 = v From the conservation of linear momentum, ⇒ ω L 2 - v c m = v ⇒ ω L 2 + L 6 = 2 v ∴ ω = 3 v L

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