[ExI] A Lawn sprinkler

John K Clark jonkc at att.net
Wed Jun 13 05:19:03 UTC 2007

You pump water through an S shaped lawn sprinkler and it spins
counterclockwise, but suppose you put the sprinkler in a tank of water and
pump water out not in. What direction will the sprinkler rotate? As an
undergraduate Richard Feynman actually tried the experiment but he was not
successful; the tank burst flooding the lab and he almost got kicked out of
school. However he later figured out what the answer must be.

 John K Clark

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