Question

A spinning ball is moving in a direction opposite to the direction of the wind. The ball moves in a curved path as:

• A. the pressure at the top and the bottom of the ball are equal.
• B. the pressure at the top > the pressure at the bottom
• C. the pressure at the top < the pressure at the bottom
• D. there is no relation between the pressures.

Answer 1

Answer: (B)

the pressure at the top > the pressure at the bottom

We use the Bernoulli's principle here. At the top, the ball and the wind flow in the opposite direction, thus the viscous force of due to the ball surface drags the air around it at lesser velocity, thus the pressure on this side is high. At the bottom the viscous force drags the air with more velocity, thus the pressure at this side is low.