$($lo grades$)$ A pipe working as a siphon connects two reservoirs as shown in the figure. Find the flow within the system and find how high $($h$)$ the pipe can be taken up above the upper reservoir such that the pressure at the Apex $($B$)$ does not fall $8m$ of water head below the atmospheric pressure. Given: Smooth pipe, pipe diameter is $D=40cm,L_{AB}=270m,L_{\text{A}\text{B}\text{C}}=1500m.$