Question

A rectangular channel 4 m wide shows a wavy surface at a depth of 2.5 m, the rate of discharge in the channel (in $m^3$/sec ) is.

• A. 49.5

Answer 1

The correct option is A 49.5
The wavy surface indicates the critical condition

$y_c=2.5m$

${\left(\frac{q^2}{g}\right)}^{1/3}=2.5$

$q=\sqrt{(2.5{)}^3\times 9.81}$

$=12.38m^3/sec/m$

$Q=qB$

$=12.3\times 4$

$=49.5m^3/sec$