function odeexample
clear all
tr=[0 15]; %seconds
initv=0; %start 600 m high
[t,y]=ode45(@f, tr, initv);
plot(t,y)
ylabel('v (m/s)')
xlabel('time(s)')
%
function rk=f(t,y)
mass=80;
k=4/15;
g=9.81;
rk= -g-k*y*abs(y)/mass;