Answer:
The flow velocity reduces to 0.72 m/s
Explanation:
According to the equation of continuity discharge in the channel should remain same
Thus we have
[tex]A_{1}V_{1}=A_{2}V_{2}[/tex]
For a rectangular channel we have [tex]Area=Depth\times Width[/tex]
Applying values in the continuity equation and since the width of the channel remains constant 3.0 m we have
[tex]3\times 1.8\times 1.2=3\times 3\times V_{2}\\\\\therefore V_{2}=\frac{6.48}{9}=0.72m/s[/tex]
