$5\mathrm{.}1\mathrm{.}5.$ A $2-$m wide rectangular channel with a bed slope of $0\mathrm{.}0005$ has a depth of flow of $1\mathrm{.}5$ meter.

Manning$$s roughness coefficient is $0\mathrm{.}015.$ Determine the steady uniform discharge in the channel. $[5]$

$5\mathrm{.}2\mathrm{.}3.$ Compute the critical depth for the channel in Problem $5\mathrm{.}1\mathrm{.}5.$