This is a Civil engineeeing hydraulics lectures homework. Q$2)$ A channel with flood plain is given with shown specifications. Calculate: a$)$ The flow rate when only the main channel is transporting water with $5$ m depth, b$)$ the depth value $y$ in the flood plain when the total discharge in the channel is $880\frac{m^3}{s}$ in a flood scenario.

$J=0\mathrm{.}0009$