Bernoulli’s Principle

Conceptual Physics

Text Correlation: Section 20.8

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Question 1

• Do the strings on the baseball playa role in curving?

• Answer: Yes, indeed. A perfectly smooth ball would not produce the same effect, for the rough parts carry air along (hence the strings on baseballs and the fuzz on tennis balls!) .The thin layer of air at the surface affects the flow separation of the general flow.

Question 2

• A table tennis ball can hover in an air stream, a demonstration of air blowers and vacuum cleaners. Is the curving of a baseball related to the hovering of table tennis balls in air streams?

• Answer: Yes. In the case of the hovering table tennis balls, they are at rest and the air moves, while in the case of the tossed baseball, the air is at rest and the ball moves. In both cases, there is relative motion between the balls and the air.