question_answer

A small disc is on the top of a hemisphere of radius \[R\]. What is the smallest horizontal velocity v that should be given to the disc for it to leave the hemisphere and not slide down it ? [There is no friction]               [CPMT 1991]

A)             \[v=\sqrt{2gR}\]

B)                      \[v=\sqrt{gR}\]

C)             \[v=\frac{g}{R}\]

D)                      \[v=\sqrt{{{g}^{2}}R}\]