don't know if this is where this would qualify under puzzels...but it is a very intresting science question.



"Take one of those spinning sprinklers everyone has seen before, the kind that has two pipes sticking out with the ends slightly bent to the side in opposite directions. Let's say the sprinkler normally turns clockwise when shooting water. Hook a hose from the sprinkler to a water pump. Submerge the sprinkler in water, so that now when you turn on the pump, water is drawn through the sprinkler's pipes. What happens to the sprinkler?

Note: From Surely You're Joking, Mr. Feynman! by Richard Feynman. Originally a problem hotly debated among Princeton physicists in the 1940s. Feynman resolved the problem by conducting an experiment that resulted in the shattering of a glass tank and ultimately getting banned from a lab."

your thoughts????

*giggles* im on school holidays so that just zoomed past my head
lol
no its interesting

edit: meeany bums! they shouldnt have banned him for shattering glass

I would be inclined to believe that the sprinkler would turn counter clockwise....is there an answer to this?

yes, there is...i think...


but i won't post it until more ideas are posted.

ok, ive thought about it for a while, tell me if im right....
it wouldnt spin at all, it may spin to begin with, but then the energy needed to pump the water would decrease...causing the sprinkler to stop...

this what i think... i should have just posted it at the beggining.

it seems to me that when the sprinkler "sucks" in the water it wants to move in the direction that the open end of the tube is facing but, when the water enters the tube it hits the inside wall of the tube and propels it in the opposite direction. because of these two forces pulling against each other they cancel each other out. You have to also factor in the viscosity of the water, this also has a "breaking affect on the sprinkler.

Therefore I think that the sprinkler would remain stationnairy.

agreed tiddlyjen