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JEE Main202331 Jan 2023Morning ShiftPhysicsCenter of Mass, Momentum and CollisionActual

100 balls each of mass m moving with speed v simultaneously strike a wall normally and reflected back with same speed, in time t s . The total force exerted by the balls on the wall is

Options

  1. A100 m v t
  2. B200 m v t
  3. C200   m v t
  4. Dm v 100 t

Correct answer

B. 200 m v t

Step-by-step solution

. Force exerted by each ball is F = ∆ p ∆ t , here, p is momentum and t is time. So, for one ball F = m v - m - v t = 2 m v t Now, total force exerted by the balls on the wall is F n e t = 100 × F = 200 m v t .

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