Which statement relates to Bernoulli's principle?

Which statement relates to Bernoulli's principle?

• A. Air traveling faster over the curved upper surface of an airfoil causes lower pressure on the top surface.
• B. Air pressure increases on the top surface with speed.
• C. Pressure differences are independent of speed.
• D. Lift arises from higher pressure on the bottom surface.

Answer: (A)

Bernoulli's principle shows that faster flow results in lower static pressure. On an airfoil, air must speed up as it moves over the curved upper surface, so the static pressure there drops. The air on the bottom moves more slowly and keeps higher pressure. This pressure difference pushes the wing upward, creating lift. So the statement that faster air over the curved upper surface causes lower pressure on the top is the one that aligns with Bernoulli’s principle and explains how lift arises. The other options contradict the relationship between speed and pressure or describe lift in an incomplete way, such as attributing lift solely to bottom pressure or claiming pressure differences don’t depend on speed.

Bernoulli's principle shows that faster flow results in lower static pressure. On an airfoil, air must speed up as it moves over the curved upper surface, so the static pressure there drops. The air on the bottom moves more slowly and keeps higher pressure. This pressure difference pushes the wing upward, creating lift. So the statement that faster air over the curved upper surface causes lower pressure on the top is the one that aligns with Bernoulli’s principle and explains how lift arises. The other options contradict the relationship between speed and pressure or describe lift in an incomplete way, such as attributing lift solely to bottom pressure or claiming pressure differences don’t depend on speed.