// problem 6.4
u=1.5/98.1
s=0.81
d=0.14
Q=0.03
g=9.81
p=s*1000/g
a=3.142*d*d/4
V=Q/a
Rn=V*p*d/u
disp(Rn,"Rn less than 2000, flow is laminar")