Question

Air streams horizontally past an air plane. The speed over the top surface is 60 m/s and that under the bottom surface is 45 m/s.The density of air is $1.293kg/m^3$, then the difference in pressure is.

• A. 1018 $N/m^2$
• B. 516 $N/m^2$
• C. 1140 $N/m^2$
• D. 2250 $N/m^2$

Answer 1

The correct option is A 1018 $N/m^2$

$\begin{array}{c}\frac{V^2}{2}+gh+\frac{p}{d}=constant\\ d=density\\ R=pressure\\ \frac{V_t^2}{2}+\frac{P_t}{d}=\frac{V_B^2}{2}+\frac{P_B}{d}\\ P_B-P_t=\frac{d}{2}\left(V_t^2-V_B^2\right)=1018N/M^2\\ where{V}_t+V_B=speedsovertopandbottom\\ K.\in =\frac{1}{2}\times 100\times {\left(11150\right)}^{2}m/s\\ =6.2\times {10}^{9}joules\\ \in scopevelocity=11.15KM/s=11150m/s\end{array}$