A solid cylinder having radius $$R$$ and length $$L$$ is slipping on a rough horizontal plane. At time $$t = 0$$ the cylinder has a translational velocity $$v_0 = 49$$ m/s, perpendicular to its axis and a rotational velocity $$v_0/4R$$ about the centre. The time taken by the cylinder to start rolling is __________ seconds. (coefficient of kinetic friction $$\mu_K = 0.25$$ and $$g = 9.8$$ m/s$$^2$$)