Flow rate of a Venturi tube

A horizontal Venturi tube through which water flows has cross section $12\mathrm{c}{\mathrm{m}}^2$ in the wide section and $4.0\mathrm{c}{\mathrm{m}}^2$ in the constriction; the pressure difference between the two sections is $2.4\cdot 10^3\mathrm{Pa}$. Compute the velocity in the wide section and the flow rate.