According to Bernoulli's principle, what happens to the pressure above the wing when air moves faster over it?

• A. Pressure decreases
• B. Pressure increases
• C. Pressure remains constant
• D. Pressure becomes zero

Answer: (A)

When air speeds up, static pressure drops. So, as air moves faster over the wing, the static pressure on the upper surface decreases. That lower pressure on top, compared with the higher pressure beneath, creates the upward lift that supports the wing. The other options don’t fit because faster flow does not raise the static pressure, nor does it keep it constant, and it certainly doesn’t drive it to zero under normal flight conditions. In real life, lift also involves how the wing shapes and deflects air, but the essential idea here is that faster air over the top reduces pressure there.