$7\mathrm{.}2$ A $21\mathrm{.}5$ kg flow of water is dynamically and thermally developed in a $12$ cm inner diameter pipe. The pipe is held at $\backslash (90^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash )$ and pipe inner surface is smooth. Find heat transfer coefficient and friction factor where the bulk temperature of the fluid has reached $\backslash (50^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash ).$