$4$ The side slopes bottom width, and lining material of the trapezoidal open

channel shown below are being designed Side slopes ranging from $12(1$

vertical to $2$ horizontal$)$ to $15$ can be selected in the design A bottom width

that ranges from $50m$ to $100m$ is permitted The Manning's $n$ for the

available lining materials is indicated in the table below The open channel

has a longitudinal slope of $05\%$ and is to carry a design flow of $2\frac{m^3}{s}$

a$)$ Choose side slopes, a bottom width, and a lining material to meet the design

flow In your design, the water depth must be between $5m$ and $8m$

b$)$ For your design in a$),$ calculate the water depth for a longitudinal channel

slope of $07\%$

Table Manning $n$ for channel lining materials