An incompressible flow is now moving through this circular pipe $($D$=0\mathrm{.}2$m$).$ The fluid passing through the duct has a density of $4\mathrm{.}2$kg$/$m$3$ and a dynamic viscosity of $1*10^-5$ kg$/$ms$.$ Where the mean velocity, centreline velocity, flow rate and pressure drop are related. The inlet velocity is now steadily increased such that the flow transitions from laminar to turbulent. Find the flow rate when the flow becomes turbulent.