If airspeed increases while angle of attack remains constant, what happens to lift?

If airspeed increases while angle of attack remains constant, what happens to lift?

• A. Lift remains unchanged due to AoA.
• B. Lift decreases.
• C. Lift increases.
• D. Lift becomes negative.

Answer: (C)

Increasing airspeed at a fixed angle of attack raises lift because lift is proportional to dynamic pressure, q = 1/2 ρ V^2, multiplied by the wing area and the lift coefficient (L = q S Cl). With a constant angle of attack, Cl stays roughly the same over normal operating ranges, so as speed increases, q grows with V^2 and lift increases accordingly. In other words, faster flow over the wing boosts the pressure difference between the top and bottom surfaces, producing more lift. The other options don’t fit this relationship: lift doesn’t stay the same at higher speed, it doesn’t decrease, and it doesn’t become negative under normal positive angle of attack.

Increasing airspeed at a fixed angle of attack raises lift because lift is proportional to dynamic pressure, q = 1/2 ρ V^2, multiplied by the wing area and the lift coefficient (L = q S Cl). With a constant angle of attack, Cl stays roughly the same over normal operating ranges, so as speed increases, q grows with V^2 and lift increases accordingly. In other words, faster flow over the wing boosts the pressure difference between the top and bottom surfaces, producing more lift. The other options don’t fit this relationship: lift doesn’t stay the same at higher speed, it doesn’t decrease, and it doesn’t become negative under normal positive angle of attack.