The flow speeds of air on the lower and upper surfaces of the wing of an aeroplane are $v$ and $2v$ respectively. The density of air is $\rho $ and surface area of wing is $A$ . The dynamic lift on the wing is 

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  • A

    $\frac{1}{2}\rho {v^2}\,A$

  • B

    $\rho {v^2}\,A$

  • C

    $\frac{3}{2}\rho {v^2}\,A$

  • D

    $2\rho {v^2}\,A$

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