Water at $25$C $($u$=0\mathrm{.}6*10^-3$ kg$/$m$.$s$)$ flows through a common steel tube $(=4\mathrm{.}6*10^-5$ m$),$ with a nominal diameter of $2"$ and a length of $25$ m$.$ The pressure gauges indicate $20$ psig at the beginning of the pipe and $10$ psig at the end. Determine the average velocity $($Use Karman graph$).$ $=$Re$($f$\_$D$)$ Gr$$fico de Karman