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NTA Abhyas JEE Main2020PhysicsLaws of MotionPractice

The figure below shows the top view of a hollow cylindrical room having a frictionless floor. A block of mass m is projected with a speed v , on the smooth horizontal floor, along the wall of the room. The average normal force exerted by the cylindrical walls, on the block, during its motion from A to B is

Options

  1. Am v 2 R
  2. Bm v 2 π R
  3. C2 m v 2 R
  4. D2 m v 2 π R

Correct answer

D. 2 m v 2 π R

Step-by-step solution

The change in momentum of the block from A to B is Δ p = 2 m v The time it takes to move from A to B is Δ t = π R v The average force exerted by the wall on the block is F avg = ∆ p ∆ t = 2 m v 2 π R

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