This is on Fluid Mechanics in Open-Channel Flow.

Water is flowing on a channel whose bottom slope is 0.002. The cross-section of the channel is shown in the figure. The channel has an unfinished cement surface (n = 0.014) at subsections 1 and 2, and a light brush (n = 0.05) at subsection 3. With the given dimensions and Manning coefficients, determine the channel's flow rate and the channel's effective Manning coefficient.

2 3 G G H A B C D E F