# Calculate velocity on the airfoil.

Calculate the velocity at a point on the airfoil, where the pressure is $${\rm{0}}{\rm{.4 \times 1}}{{\rm{0}}^{\rm{5}}}{\rm{N/}}{{\rm{m}}^{\rm{2}}}$$. The free stream velocity is $${\rm{70m/s}}$$ in a standard sea level conditions.

Asked on 28th December 2018 in
At sea level conditions $${{\rm{\rho }}_\infty }{\rm{ = 1}}{\rm{.23kg/}}{{\rm{m}}^{\rm{3}}}$$ and  $${p_\infty }{\rm{ = 1}}{\rm{.01}} \times {\rm{1}}{{\rm{0}}^5}{\rm{N/}}{{\rm{m}}^{\rm{2}}}$$${p_\infty } + \frac{1}{2}\rho v_\infty ^2 = p + \frac{1}{2}\rho {v^2}$$v = \sqrt {\frac{{2\left( {{p_\infty } – p} \right)}}{\rho } + v_\infty ^2}$$v = \sqrt {\frac{{2\left( {1.01 – 0.4} \right) \times {{10}^5}}}{{1.23}} + {{\left( {70} \right)}^2}}$$\Rightarrow v = 322.63\,{\rm{m/s}}{\rm{.}}$