%miscarea pe suprafata interna a cilindrului;

r=2;
v0=0.5;
alfa=pi/4;
g=9.8;
t0=0;tf=200;
t=t0:0.01:tf;
x=r*cos(v0*cos(alfa)/r*t);
y=r*sin(v0*cos(alfa)/r*t);
z=20000-(0.5*t.*t+v0*sin(alfa)*t);
comet3(x,y,z)