# Fluid mechanics Questions - Manning's Formula

11) The angle between the tow sloping sides of a standard triangular weir is 60 degrees. When the head of the crest of the weir is .525ft, the rate of discharge, in cubic feet per second, would be? .405 cfs, .331 cfs, .368 cfs, .294 cfs.

12) The diameter of a circular sewer is 42 in., and the rate of slope is .0008. If Manning's formula is to be used and the value of n is taken as .016, the rate of discharge, in cubic feet per second, when is the sewer half full of liquid? 23.2 cfs, 15.4 cfs, 19.3 cfs, 11.6 cfs.

13) The velocity in a circular channel that is 6 ft. in diameter and is half full of liquid is 5.62 fps. When the depth of the liquid is 2.70 ft., what is the velocity? 5.34 fps. 4.70 fps, 5.05 fps, 4.30 fps.

14) A sewer is to be built of concrete pipe for which the value of n may be taken as .013. The rate of slope is to be .0002 and the rate of discharge when the sere is half full of liquids is to be 22.0 cfs. If Manning's formula may be used, the diameter of the smallest pipe that would be suitable is 66 in., 48 in., 54 in., 42 in.

15 A flume is to have a rectangular cross section, and its width is to be twice the depth of the water when the rate of discharge is 100 cfs. The rate of slope is to be .001. If the Manning's formula may be used and man be taken as .013, the theoretical with of the flume should be? 6.96 ft, 6.36 ft. 6.66 ft, 6.06 ft.

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#### Solution Summary

Fluid Mechanics Questions using Manning's formula.