A $400-$m long pipeline has a $250-$mm diameter cast iron pipe $($ks $=0\mathrm{.}046$ mm$).$ If the flow

in the pipe is $80$ L$/$s $(0\mathrm{.}08$ m$3/$s$),$ find the head loss $($in m$)$ and the shear stress $($in N$/$m$2).$

Assume that the water has a kinematic viscosity $()$ of $1\mathrm{.}3$ x $10-6$ m$2/$s and a specific

weight $()$ of $9\mathrm{.}8$ kN$/$m$3,$ and that the acceleration of gravity is $9\mathrm{.}81$ m$/$s$2.$