A particle A A\,A of mass 3 kg and a particle B B\,B of mass 6 kg are connected by a light inextensible string. The string passes over a smooth pulley fixed at the top of a rough inclined plane. The coefficient of friction between the particle A A\,A and the plane is 0.25. The plane is inclined at an angle of α∘ \alpha^\circ\,α∘ to the horizontal such that cosα=0.6\cos \alpha = 0.6cosα=0.6. A A\,A lies on the plane and B B\,B hangs freely from the edge of the plane 1.5 m above the ground with the string taut. The system is released from rest. Assume B B\,B hits the ground before A A\,A reaches the pulley.
Find the speed at which B B\,B hits the ground.