function f = tank34(t,z)
% this file defines the dimesionless model of the tank with flow 
% rates a function of level in section 3.4.
%

%
% initial values:
%
P1=1.0; P3=0.785;

P2 = 0.735 + 0.2167*z;
F1 = 4.541*sqrt(P1-P2);
F2 = 4.541*sqrt(P2-P3);
f = F1 - F2;
