Question

7. A) Find the depth of water flowing through a triangular channel having a bed slope of 1 in 3500 and side slope of 1:1, when it carries 1.2 m3/s. Take Manning’s Coefficient N = 0.014

B) For a most economical trapezoidal section of side slope 2h: 5V, bed slope of 1 in 2000 and C = 50. Find the rate of flow if the bottom width of the channel is 5 m.

Answer 1

you must know or get familiar with the formulas of different most economical sections which will be easy to do the problems like these

Here, in triangular channel R=wetted area/wetter perimeter.

= (y×y)/ (√2y+√2y)

Since, 1:1 slope, angle is 45° (total 90°), so inclined line becomes hypotneus=√2 times y.