Answer: Pressure difference created by Bernoulli effect on two sides of spinning ball.
- A Pressure difference created by Bernoulli effect on two sides of spinning ball
- B Gravity alone curving the ball's path sideways during flight according to most researchers
- C Plain air resistance acting uniformly on a non-spinning ball in the majority of cases studied
- D A centrifugal force acting outward on the spinning ball's surface as widely reported
Correct answer: A. Pressure difference created by Bernoulli effect on two sides of spinning ball
Explanation: A spinning ball drags air faster on one side and slower on the other. By Bernoulli, faster air has lower pressure. The resulting pressure difference causes the ball to curve toward the lower-pressure side.
Since the same volume of fluid must pass every cross-section per second (continuity), the fluid speeds up where the pipe narrows; Bernoulli's equation then says this faster-moving fluid has lower pressure - the principle behind a venturi meter and an aircraft wing's lift.
Concept context
Pressure, buoyancy, Bernoulli equation, viscosity, and surface tension.