In a test experiment on a model aeroplane in wind tunnel, the flow speeds on the upper and lower surfaces of the wings are $$70$$ m s$$^{-1}$$ and $$65$$ m s$$^{-1}$$ respectively. If the wing area is $$2$$ m$$^2$$, the lift of the wing is _______ N. (Given density of air $$= 1.2$$ kg m$$^{-3}$$)