JEE Mains · Physics · STD 11 - Fluid mechanics
- JEE Mains 2024
- Hard
- Numerical
In a test experiment on a model aeroplane in wind tunnel, the flow speeds on the upper and lower surfaces of the wings are \(70 \mathrm{~ms}^{-1}\) and \(65 \mathrm{~ms}^{-1}\) respectively. If the wing area is \(2 \mathrm{~m}^2\) the lift of the wing is _______ \(\mathrm{N}\). (Given density of air \(=1.2 \mathrm{~kg} \mathrm{~m}^{-3}\) )
Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \(810\)
Step-by-step Solution
Detailed explanation
\(\mathrm{F}=\frac{1}{2} \rho\left(\mathrm{v}_1^2-\mathrm{v}_2^2\right) \mathrm{A}\)
\(\mathrm{F}=\frac{1}{2} \times 1.2 \times\left(70^2-65^2\right) \times 2\)
\(=810 \mathrm{~N}\)
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