A vertical pipe $0\mathrm{.}56m$ in diameter and $18m$ long has a pressure head at the upper

end of $5\mathrm{.}5m$ of water. When the flow of water through it is such that the mean

velocity is $5m{s}^{-1},$ the friction loss is $h_L=1\mathrm{.}29m.$ Find the pressure head $($in $m)$ at the

lower end of the pipe when the flow is downward.DOWNWARD!!$1$