Rotational dynamics

The three identical spheres, each of mass m, are supported in the vertical plane on the $30^\circ$ incline. The spheres are welded to the two connecting rods of negligible mass and equal length. The upper sphere is pivoted freely to a rod of negligible mass and length $\SI{0.49}{m}$ whose other end is attached to a bracket at A. If the stop at B is suddenly removed, determine the velocity $v$ (in $ms^{-1}$ ) with which the upper sphere hits the incline.

Note: Assume pure rolling.