$S2(\frac{35}{100}).$ In a shell$-$tube heat exchanger, $10000k\frac{g}{?}$ hour of water will be heated from $16C$ to $84C$ with hot engine oil flowing through the body. The oil makes a single body passage entering at $160C$ and exiting at $94C,$ with an average heat transfer coefficient ho $=400\frac{W}{m^2}K.$ Water flows through $11$ brass pipes with an inner diameter of $22\mathrm{.}9mm$ and an outer diameter of $25\mathrm{.}4mm,$ with each pipe making eight passes through the body. Assuming fully developed flow for water, determine the required pipe length per pass. Assume negligible pollution impacts.