A small ball `B` of mass `m` is suspended with light inelastic string of length `L` from a block `A` of same mass in which can move on smooth horizontal surface as shown in the figure. The ball is displaced by angle `theta` from equilibrium position and then released.

Maximum velocity of block during subsequent motion of the system after release of ball is

Options

A. `[gl(1-costheta)]^(1//2)`
B. `[2gl(1-costheta)]^(1//2)`
C. `[glcostheta]^(1//2)`
D. informations are insufficient to decide

Answer

A