COMEDK · Physics · 11. Mechanical Properties of Fluids
The speeds of air-flow on the upper and lower surfaces of a wing of an aeroplane \(arefv_1\) and \(v_2\), respectively. If \(A\) is the cross-sectional area of the wing and \(\rho\) is the density of air, then the upward lift is
- A \(\frac{1}{2} \rho A\left(v_1-v_2\right)\)
- B \(\frac{1}{2} \rho A\left(v_1+v_2\right)\)
- C \(\frac{1}{2} \rho A\left(v_1^2-v_2^2\right)\)
- D \(\frac{1}{2} \rho A\left(v_1^2+v_2^2\right)\)
Answer & Solution
Correct Answer
(C) \(\frac{1}{2} \rho A\left(v_1^2-v_2^2\right)\)
Step-by-step Solution
Detailed explanation
Due to the specific shape of wings, when the aeroplane runs, air passes at higher speed over it as compared to its lower surface. This difference of air speeds above and below the wings, in accordance with Bernoulli's principle, creates a pressure difference, due to which an…
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