A sphere fo mass m makes SHM in a hemispherical bowl ABC and it moves from A to C and back to A via ABC, so that PB = h. If acceleration due to gravity is g, the speed of the ball when it just crosses the point B is

Options

A. ` 2gh `
B. `gh `
C. ` sqrt ( 2gh ) `
D. ` sqrt ( 5 gh ) `

Answer

C

Explanation

From figure, of hemispherical bowl ABC, potential energy at A is converted into kinetic energy at B.
` therefore mgh = ( 1 ) / ( 2) mv _ B^ 2 rArr v _ B = sqrt( 2gh ) `