function unknownsDerivatives = Galileo1(tValue,unknowns,R)

s=unknowns(1);
v=unknowns(2);

g=9.81;
rhoIron=9000;
rhoAir=1.225;


dsdt=v;
dvdt=g-.4*0.5*rhoAir*pi*R^2/(rhoIron*4*pi*R^3/3)*unknowns(2).^2;

unknownsDerivatives(1)=dsdt;
unknownsDerivatives(2)=dvdt;

unknownsDerivatives=unknownsDerivatives';

end

