Numerical Solutions $($Open Method$)$ : Water is flowing in a trapezoidal channel at a rate of $Q=(A+B).$ The critical depth $y$ for such a channel must satisfy the equation:

$0=1-\frac{Q^2}{g{A}_c^3}B$

where $\text{'}g\text{'}$ is the acceleration due to gravity, is the cross$-$sectional area $(),$ and B is the width of the channel at the surface $(m).$ For this came the width and the cross$-$sectional area can be related to depth $y$ by:

$B=3+y,$ and $,A_c=3y+\frac{y^2}{2}$

Solve for $y$ using three methods. Initial values and intervals should be in the right parameter. Iterate manually until the given is satisfied.

Solve $2$ times using A $=2,$ B $=6$; and A$=3,$ B $=4$