function [ f ] = force_sol( L,U,P,b )
b = P*b;
[n,n] = size(L);
for k = 1:n
s = 0;
for p = 1:(k-1)
s = s + L(k,p)*C(p);
end
C(k) = b(k) - s;
end
for k = n:-1:1
t = 0;
for p = (k+1):n
t = t + U(k,p)*f(p);
end
f(k) = (C(k) - t)/U(k,k);
end
f=f';

3, u The pressure drop needed to force water
through a horizontal 1-in.-diameter pipe is 0.60
psi for every 12—ft length of pipe. Determine the
'shear stress on the pipe wall. Determine the shear
stress at distances 0.3 and 0.5 in. away from the
pipe wall

Problem set #8
1) A large artery in a persons body can be approximated by a tube of diameter 9 mm and length 0.35
m. Also assume that blood has a viscosity of approximately 4 x 10 -3 Ns/m2, a specific gravity of 1.0,
and that the pressure at the beginning

8.8
8.8 A soft drink with the properties of 10 °C
water is sucked through a 4-mm—diameter, 0.25-
m-long straw at a rate of 4 cm3/s. Is the ﬂow at
the outlet of the straw laminar? Is it fully devel-
oped? Explain.
= 0.319% ms, may z/=I.arx/o"é”-‘(seem/eazl