A large tank of cross-section area A contains liquid of density $\mathrm{\rho }$ . A cylinder of density $\frac{\mathrm{\rho }}{4}$, length  $l=40cm$, and cross-section area $\mathrm{a} (<< \mathrm{A})$ floating in the liquid. It is pushed inside the liquid so that it is just submerged and then released at $t = 0$. Assuming that the water level in the tank remains constant, determine the speed (in m /s) of the cylinder when it reaches its equilibrium position for the first time. Neglect viscous forces. $\left[\text{ Take }\mathrm{g}=10{ \mathrm{ms}}^{-2}\right]$