Water flows through a rectangular channel with a

unit flow rate $q=1\mathrm{.}5\frac{m^2}{s}.$ At point $(1),$ the water

depth is $0\mathrm{.}5m.$ The head loss between points $(1)$ and $(2)$

is $0\mathrm{.}03m.$

$($a$)$ Draw the energy grade line between points $(1)$ and

$(2)$ and determine if the flow conditions at points $(1)$

and $(2)$ are subcritical, critical, or supercritical.

$($b$)$ Explain why the head loss could be $0\mathrm{.}06m.$