Question

An airplane wing is designed so that the speed of the air across the top of the wing is 297 m/s when the speed of the air below the wing is 209 m/s. The density of the air is 1.29 kg/m3. What is the lifting force on a wing of area 26.0 m2?

Answer 1

Answer:

The value is   $F_L = 759200 \ N$

Explanation:

From the question we are told that

   The speed of air across the top of its wings is  $v = 297 \ m/s$

   The speed of air below  its wings is $u = 209 \ m/s$

    The density of air is $\rho = 1.29 \ kg/m^3$

     The area of the wing is  $A = 26.0 \ m^2$

Generally the lifting force is mathematically represented as

             $F_L = \Delta P * A$

Here  $\Delta P$ is the difference in kinetic energy density between the top and the bottom  

   $\Delta P = \frac{1}{2} * \rho * [v^2 - u^2 ]$              

=>     $\Delta P = \frac{1}{2} * 1.29 * [297^2 - 209^2 ]$

=>     $\Delta P = 2.92 *10^{4} \ Pa$

So  

      $F_L = 2.92 *10^{4} * 26.0$

=>   $F_L = 759200 \ N$