The sewage discharge in a detritus tank of a treatment plant is 576 litres/sec with flow velocity of 0.2 m/sec. If the ratio of width to depth is 2, the depth is

Given.

Q = 576 lit/sec, means Q = 0.576 m^3/sec because (1 m^3 = 1000 lit).

Also given v = 0.2 m/sec.

We know that Q = A*V,

So A = Q/V = 0.576/0.2 = 2.88 m^2,

Also given width/depth = 2 means b = 2*d.

So A = b*d = 2.88, given b = 2d.

So 2d*d = 2.88. So d^2 = 1.44.

So d =under root 1.44, d = 1.2 m = 1.2*100 = 120 cm.