The figure below shows a thin, uniform bar of length D = 1.28 m and mass M = 0.67 kg pivoted at the top. The rod, which is initially at rest, is struck by a particle whose mass is m = 0.30 kg at a point x = 0.80d below the pivot. Assume that the particle sticks to the rod. If the maximum angle between the rod and the vertical following the collision is 60°, find the speed of the particle before impact.