Consider a uniform cross-sectional closed vessel with its lower part filled with incompressible and non viscous liquid of density ‘d’ up to height ‘9h’ and upper part filled with ideal monoatomic gas to a height ‘h’. The liquid and gas are separated by a movable insulating massless piston. Assume that initial pressure of the gas is $32 P_0$, where  $P_0$ is the atmospheric pressure. There is an orifice at the bottom of the vessel. If the gas expands adiabatically to a length 8h. Then the instantaneous efflux velocity of the liquid is $\sqrt{xhg}$  The value of $x$ is ($g$ is the acceleration due to gravity).