Prob. $8\mathrm{.}5\mathrm{.}37$ p$.$ IP$-113[$Ans: $0\mathrm{.}44ft].$

$8\mathrm{.}5\mathrm{.}37$ WP A certain process requires $2\mathrm{.}3f\frac{t^3}{s}$ of water to be delivered at a pressure of $30.$ This water comes from a large$-$diameter supply main in which the pressure remains at $60.$ If the galvanized iron pipe connecting the two locations is $200ft$ long and contains six threaded $90$ elbows, determine the pipe diameter. Elevation differences are negligible.