A ring of mass m can slide over a rough vertical rod with coe of friction   as shown.The ring is connected to a spring of force constant k=4mg/R . 2R is the natural length of the spring. The other end of the spring is fixed to the groung at a horizontal distance 2R. from the base of the rod. If the mass is released at a height of 1.5 R , and the velocity on reaching the ground is

(3gr) . Find .

 

 

ans = 0.549