Two small spheres A and B, each of mass m, are attached at either end of a rod of length d...

Two small spheres A and B, each of mass m, are attached at either end of a rod of length d. The system is released from rest in the position shown. Neglect friction, treat the spheres as particles (assume that their diameter is negligible), neglect the mass of the rod, assume the rod is rigid, and assume that d < R. Hint: The force that the rod exerts on either ball has the same direction as the rod itself.

Figure P3.105

Determine the expression for the speed of the spheres immediately before B reaches point D.