Question

If air speed is greater along the top surface of a bird's wings, pressure of the moving air there is _______.

unaffected

reduced

increased

turbulent

Answer 1

By Bernuolli's equation we know that

`(1)/(2)\rho v_1^2 + \rho gh_1 + P_1 = P_2 + (1)/(2)\rho v_2^2 + \rho g h_2`

now since we know that height is almost same for two sides of wing

now we will have

`(1)/(2)\rho v_1^2 + P_1 = (1)/(2)\rho v_2^2 + P_2`

now pressure on lower side of wing must be more than the pressure on the upper side

`P_1 - P_2 = (1)/(2)\rho(v_2^2 - v_1^2)`

so speed on the top is more than the speed at the bottom

so correct answer will be

If air speed is greater along the top surface of a bird's wings, pressure of the moving air there is REDUCED.