Water $({}_{\text{w}\text{a}\text{t}\text{e}\text{r}}=1000k\frac{g}{m^3},=1cp)$ is flowing in a pipe of $1m$ under laminar conditions $)=(1600.$ Calculate the pressure difference due to friction loss in different cases; $1^{st}$ case: vertical pipe downward flow, $2^{nd}$ case: vertical pipe upward flow, $3^{rd}$ case: Horizontal pipe. $(P_0-P_L$ and hydrodynamic pressure difference $P_0-P_L$ under the following conditions.$)$ Make evaluations separately for options a and $b.$

a$)$ When $D=1\mathrm{.}6mm,V_{\text{a}\text{v}\text{e}}$ of water $=1\frac{m}{s}.$

b$)$ When $D=16mm{V}_{\text{a}\text{v}\text{e}}$ of water $=0\mathrm{.}1\frac{m}{s}$