Answer:
manning's coefficient is 0.0357
Explanation:
Given:
Velocity of flow, v = 12 m/s
Width of the channel, b = 6 m
Depth of the channel, d = 2 m
bed slope, s = 0.001
mean velocity of flow, V = 1 m/s
now, the velocity is given as:
[tex]V= \frac{1}{n}R^{\frac{2}{3}}S^{\frac{1}{2}}[/tex]
where,
n is the manning's coefficient
R is hydraulic mean depth
R = (Area of the channel) / (wetted Perimeter of the channel)
now,
R = (2 × 6) / ((2 × 2) + 6)
or
R = 12 / 10 = 1.2 m
now, on substituting the values in the equation for velocity, we get
[tex]1= \frac{1}{n}1.2^{\frac{2}{3}}(0.001)^{\frac{1}{2}}[/tex]
or
[tex]n= 1.2^{\frac{2}{3}}(0.001)^{\frac{1}{2}}[/tex]
or
n = 0.0357
hence, the value of manning's coefficient is 0.0357
