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JEE Main202127 Jul 2021Evening ShiftPhysicsMotion in Two DimensionsActual

A small block slides down from the top of hemisphere of radius R = 3 m as shown in the figure. The height h at which the block will lose contact with the surface of the sphere is m . (Assume there is no friction between the block and the hemisphere)

Correct answer

2

Step-by-step solution

m g cos θ = m v 2 R       . . . ( 1 ) cos θ = h R Energy conservation m g R - h = 1 2 m v 2 . . . ( 2 ) from ( 1 ) and ( 2 )   ⇒ m g h R = 2 m g R - h R h = 2 R 3 = 2   m

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