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 ms^-1 and 65 ms^-1…

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