An aeroplane of mass $3 \times 10^4\, kg$ and total wing area of $120\, m^2$ is in a level flight at some height. The difference in pressure between the upper and lower surfaces of its wings in kilopascals is $(g=10\,m/s^2)$
A$2.5$
B$5.0$
C$10.0$
D$12.5$
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A$2.5$
a $\Delta P=\frac{F}{A}=\frac{m g}{A}=\frac{3 \times 10^{4} \times 10}{120}$
$\Delta P=2.5 \times 10^{3} P a$
$=2.5$ kilopascal
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