$3\mathrm{.}5$ A shell$-$and$-$tube type condenser is to be made with $\frac{3}{4}in.$ outer diameter $.$

inner diameter$)$ brass tubes, and the length of the tubes between tube plates is

$3$ m $.$ Under the worst conditions, cooling water is available at $21C$ and the outlet

temperature is $31C.$ Water velocity inside the tubes is approximately $2\frac{m}{s}.$ The

vapor side film coefficient can be taken as $10,000\frac{W}{m^2}*K.$ Calculate the overall

heat transfer coefficient for this heat exchanger.