For a symmetrical trapezoidal open drain in a landscape with grass and loose rock surface, the velocity of flow of water is m/sec

Q. For a symmetrical trapezoidal open drain in a landscape with grass and loose rock surface, the velocity of flow of water is m/sec, (rounded off to two decimal places), given the following data.

Water edge width at the top= 750 mm

Water edge width at the bottom = 450 mm

Water depth = 600 mm

Manning’s coefficient of roughness = 0.05 Slope along the

drain= 1 in 250

A. 4.5

B. 0.45

C. 45

D. 1.5

Ans: 0.45

Solution: