Verified Solution • 2025–26 Session moderate

QJEEM23Ph6f27: JEE Main 2023 Physics - Class 11 JEEM23Ph6f27 Solution: A fully loaded boeing aircraft has a mass of kg. Its total wing …

A fully loaded boeing aircraft has a mass of 5.4×1055.4\times10^5 kg. Its total wing area is 500 m 2^2 . It is in level flight with a speed of 1080 km/h. If the density of air ρ\rho is 1.2 kg m −3^{-3} , the fractional increase in the speed of the air on the upper surface of the wing relative to the lower surface in percentage will be. ( g=10 m/s2\mathrm{g=10~m/s^2} )

Multiple Choice Options

  • A 16
  • B 8
  • C 6
  • D 10

Step-by-Step Verified Solution

Velocity of aircraft = 1050 km/h = 300 m/s

Now, weight of aircraft = ΔPA\Delta PA

ΔP=5.4×105×g500=10800\Delta P = {{5.4 \times {{10}^5} \times g} \over {500}} = 10800 Pa\mathrm{Pa}

From Bernoulli's principle

ΔP=12ρ[Vupper2−Vlower2]\Delta P = {1 \over 2}\rho \left[ {V_{upper}^2 - V_{lower}^2} \right]

10800=12×1.2×Vlower2[(VupperVlower)2−1]10800 = {1 \over 2} \times 1.2 \times V_{lower}^2\left[ {{{\left( {{{{V_{upper}}} \over {{V_{lower}}}}} \right)}^2} - 1} \right]

(VupperVlower)2=1+10800×21.2×(300)2=1.2{\left( {{{{V_{upper}}} \over {{V_{lower}}}}} \right)^2} = 1 + {{10800 \times 2} \over {1.2 \times {{(300)}^2}}} = 1.2

VupperVlower=1.096{{{V_{upper}}} \over {{V_{lower}}}} = 1.096

⇒\Rightarrow Fractional increases = 9.6%

Related Learning Resources & Exam Preparation