$8\mathrm{.}42$ Water flow through a $6$ inch diameter horizontal pipe at a flow rate of $2\mathrm{.}0cfs.$ The pressure drop is $4\mathrm{.}2$ psi per $100ft$ of pipe. Determine $($a$)$ the friction factor and $($b$)$ type of pipe.

Ans: $($a$)f=0\mathrm{.}03,($b$)=0\mathrm{.}0025,$ so probably concrete pipe

For the in$-$class example above, consider replacing the concrete pipe with galvanized iron with the same flow rate.

a$)$ What would be the new pressure drop for the new pipe in psi?

b$)$ How much power was lost due to friction in the old concrete pipe per $100ft$ section in units of $ft-l\frac{b}{s}?$

c$)$ How much power will be lost due to friction in the pipe per $100ft$ section in units of $ft-l\frac{b}{s}?$

d$)$ What is the percent change from $($b$)$ to $($c$)?$

e$)$ Estimate the pressure drop using Hazen$-$Williams method. What is the percent change compared to your answer in $($a$)?$