Problem 4: (20 pts) Consider the liquid storage system shown below: qi is the inlet volumetric flow rate (m3/hr) q is the outlet volumetric flow rate (m3/hr) h is the liquid level (m) A is the cross-sectional area (m2), which is constant d is the density of the liquid (kg/m3), which is constant Assuming that q=Rh, where R is constant, and the tank is empty at t=0; a) write a mass balance around the tank, b) derive the transfer function that relates the change in the inlet flow rate (qi) with the liquid level (h). G(s)=Qi(s)H(s)