gc=3.0;
c=0.3;
xm2= 0.1:0.1:10;
xm1=1;
a=(2*xm1 +c)./(2*xm2+c);
b=sqrt(xm1./c+a.*a.*xm2./c+(a.*a.*a+1)./(a+1)./3);
v1= gc./b;
ratio=xm1./xm2;
plot(ratio,v1,'b+')
xlabel('ratio m1/m2')
ylabel('m1 velocity')
title('variation of v1 on ratio m1/m2')