You have a piping system in your plant that has gotten old and rusty. The pipe is $2 \mathrm{in}$. sch 40 steel, $6000 \mathrm{ft}$ long. You find that it takes $35 \mathrm{hp}$ to pump water through the system at a rate of $100 \mathrm{gpm}$.

(a) What is the equivalent roughness of the pipe?

(b) If you replace the pipe with the same size new commercial steel pipe, what percentage savings in the required power would you expect at a flow rate of $100 \mathrm{gpm}$ ?