A rectangular concrete channel (n = 0.020) changes from a mild slope to a steep slope. The

Question:

A rectangular concrete channel (n = 0.020) changes from a mild slope to a steep slope. The channel in 20 m wide throughout, and the rate of flow is 180 m3/s. if the slope of the mild portion of the channel is 0.0006 m/m, determine the distance upstream from the slope change to the point where y = 3.0 m?