A long canal with a rectangular section, with a width of $6\mathrm{.}8$ meters, Manning

number $n=0\mathrm{.}014,$ and slope of the sill $0\mathrm{.}0003,$ takes water from a

reservoir. The entry of water into said channel is controlled by a gate.

The reservoir level is $8\mathrm{.}8$ meters above the channel bottom, obtain

the longitudinal flow profile for a flow rate of $28\frac{m^3}{s}.($Assume negligible

local gate losses$)$

$8\mathrm{.}8m$