%Math4090 2010 chapter 2
%tunnelEQ.m
%
function xp=tunnelEQ(t,x)
global d P0 rho g h f L D gam
xp=zeros(2,1);
xp(1)=x(2);
p0=P0/(rho*g*h);
F=f*L/D;
xp(2)=(1+p0*(1-(1/(1-x(1)))^gam)-(sign(x(2))*F*x(1)+1)*x(2)^2)/(x(1)+d/L)/2;