clear all; clc; close all;
pkg load control

m=1/3;
k =1;
b = 2/3;

a1=b/m; a0=k/m; b0=1/m;

t = 0:0.01:10;
u = 1.*[zeros(1,100),ones(1,length(t)-100)];
p1=plot(t,u,'r-.');
hold on

A = [0    1;
    -a0 -a1];
B = [0;
     b0];
C = [1 0];
D = 0;
sys = ss(A,B,C,D);
x0 = [0 0];
lsim(sys, u, t, x0);