\[V=4S\left(h_2-h_3+L_0\right)+\frac{F}{\rho g}-\frac{2Sp_0L_0}{p_0+2\rho g\left(h_2-h_3\right)}-\frac{2Sp_0L_0}{p_0+2\rho g\left(h_2-h_3\right)+\frac{F}{S}}.\]