The Feynman inverse sprinkler problem: A demonstration and quantitative analysis

The results of an experiment designed to illustrate the effects of hooking a common lawn sprinkler to a suction, rather than to a pressure, source are presented. The inverse sprinkler moves in a direction opposite to that of the normal sprinkler with an angular momentum opposite to and approximately equal to that of the fluid in the sprinkler arms. Recent experiments designed to test this effect may have produced a null result because of friction associated with the systems. A demonstration constructed at the University of Maryland, College Park, that avoids this problem is discussed.