What is the net upward force on a airplane wing?

Question

whose area is 14.2 m^2 if the speed of flow is 392 m/s across the top of the wing, and 248 m/s across the bottom?
Use an air density of 1.29kg/m^3. (Ans. in units of N.)

Answer 1

the answer I got was 844093.44N

here is how I did it
http://img.photobucket.com/albums/v628/kerahna/physyahoo2.jpg

I hope its right XD

Answer 2

Actually, this question is bogus and i would reject ever even considering to answer it. The historical use of bernoulli's principle is incorrect. In fact, the upward force on a wing has NOTHING to do with "varying pressure caused by differential speeds of air movement accross the top and the bottom of the wing." More to the point, there was never any reason to surmise that air actually DOES travel faster accross the top of the wing than it does along the bottom.

The REAL reason lift is generated is actually due to angle of attack. the same reason your hand goes up if you hold it out the window at a 45 degree incline while on the freeway... the air bounces DOWN off the bottom of the wing. By newton's laws there is an equal and opposite reactionary force pushing upwards on the wing. This generates the lift needed to fly. I would tell your teacher the question is craptacular.