Given a constant specific energy, show that the maximum flow through a section occurs at the critical point. (0.5 pts.) Once this demonstration is done, graph the flow curve against the head for the following cases: 1) Consider three rectangular channels with widths b = 0.5 m, b = 1.0 m, and b = 2.0 m. If in each of these there is a specific energy E = 2m, how is the flow curve against the height in each channel? 2) ii. Consider a rectangular channel with width b = 1.0 m. Plot the curve of discharge against channel height for the specific energies E = 1m, E = 2 m and E = 3 m.