function wf2=wf(x)
%for droplets with 10<r<535 micron, radius specified in meters
%fall velocity is in m/s
p1=[-3.18657 .992696 -.153193e-2 -.987059e-3 -.578878e-3 .855176e-4 -.327815e-5];
ws=1e3/1.3*2*x^2/9*9.83/1.5e-5;
cdn2=32*x^3*1e3/1.3/(1.5e-5)^2*9.83/3;
xx=log(cdn2);
yy=[1 xx xx*xx xx^3 xx^4 xx^5 xx^6];
y=sum(yy.*p1);
re=exp(y);
wf2=1.5e-5*re/2/x;
%[wf ws]
   

