Problem:
A trapezoidal channel is to be excavated at a site where permit restrictions require that the channel have a bot- tom width of 5 m, side slopes of 1.5:1 (H:V), and a depth of flow of 1.8 m. If the soil material erodes when the shear stress on the perimeter of the channel exceeds 3.5 Pa, determine the appropriate slope and corresponding flow capacity of the channel.
Required:
Question: Use the Darcy-Weisbach equation and assume that the excavated channel has an equivalent sand roughness of 3 mm.
Note: Provide support for rationale.