## Airplane problem - help?

Hi everyone…I have a airplane question:

Q: The profile of a particular airplane wing is such that the distance air has to move to traverse the top of the wing is 20% greater than the distance the air must travel to traverse the bottom of the wing. (This shape is an “airfoil”.) If air is flowing steadily across the wing, then the air molecules that part ways (one to go over the top of the wing and one to go across the bottom of the wing) at the leading edge of the wing must come back together again at the trailing edge.

Calculate the lifting force generated per square foot if the wing is moving through the air at 200 mph (airspeed measured across the bottom of the wing). What size wing (in square feet) is needed to support a 3000 lb aircraft?

A: Bottom: P+½pv^2= Top: P+½v^2 because the pgy^2 cancel out
Substitute for p= (F*d)/vol

Top: v=107.28m/s; 9.8*1361.8kg=13346N; 3000lb=1361.8kg
Bottom: v=89.4m/s; F=13346N; M=13346N

13345.6N*d/vol + (.5*1361.5kg*(89.34m/s^)2)/vol= 13346N*1.2d/vol +(.5*1361.8kg*(107.28m/s)^2)/vol

-2.6696N*d = 2394479Nm
d=-896m

I think that I am on the wrong track because I came out with a negative distance. Can anyone help?