function [N1,N2,A,P] = PASM1(t,y)

rho = 1.040;
mu = 0.04;
xi = 2;
E = 2.25e6;
p_ext = 5;
l = 8.6;
h0 = 1.032;
nu = 0.5;
A0 = 1.8602;
P0 = 0;
kr = 2*(xi+2)*pi*(mu/rho);
K = (h0*E*(pi)^(0.5))/((1-nu^2)*(A0)^(0.5));

Pin = 1;%+1*sin(5*t);
Qout = 1;

V = y(1);
Q = y(2);
A = V/l;
LA = (rho*l)/A;
RA = (rho*kr*l)/(A^2);

P = (K/(A0)^(0.5))*(((A)^(0.5) - (A0)^(0.5)))+P0+p_ext;
V = Q-Qout;
Q = (1/LA)*(Pin-RA*Q-P);
N1 = V;
N2 = Q;