Problem 4: (20 pts) Consider the liquid storage system shown below: qi is the inlet volumetric flow rate (m/hr) q is the outlet volumetric flow rate (m/hr) h is the liquid level (m) 9 A is the cross-sectional area (m), which is constant d is the density of the liquid (kg/m), which is 9 constant Assuming that q=R-h, 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 (q) with the liquid level (h). H(s) G(s) = Qi(s)