Question

The pressure on the top surface of an aeroplane wing is $0.8\times {10}^5$ Pa and the pressure on the bottom surface is $0.75\times {10}^5$ Pa. If the area of each surface is $50m^2$, the dynamic lift on the wing is

• A. $0.5\times {10}^4$ N
• B. $0.25\times {10}^4$ N
• C. $5\times {10}^4$ N
• D. $25\times {10}^4$ N

Answer 1

The correct option is D $25\times {10}^4$ N

given data,

Pressure on the top surface $P_1=0.8\times {10}^{5}Pa$

Pressure on the bottom surface $P_2=0.75\times {10}^{5}Pa$

Area $A=50m^2$

Dynamic lift on the wing $F=?$

Dynamic lift on the wing

$F=(P_1-P_2)A$

$F=(0.8\times {10}^5-0.75\times {10}^5)50$

$F=(0.5\times {10}^5)50$

$F=25\times {10}^4$

the dynamic lift on the wing is $25\times {10}^4$