while the water goes out any drain..it always rotate (whirlpool) at anti-clockwise ..why is that ?

Answer 1

http://www.discovery.com/area/skinnyon/skinnyon970523/skinny1.html

Read it all the way to the end!

or, even better:
http://www.ems.psu.edu/~fraser/Bad/BadCoriolis.html

Answer 2

I'm not sure whether this is due to coriolis force but it does happens. Some people say that this happens due to the shape of the object that hold water. It's not true. I think they should try with different shapes and still find that water runs counterclockwise in the northern hemisphere and cloack wise in the southern hemisphere.

A closest explanation I got was to think of the earth as a collection of circles rather than as a globe. When the earth rotates, there will be a corresponding force towards the centre of each circle(Circular motion and centrifugal force). The culminative effect of the collection of forces on the circles will make the water turn in different directions. The earth can be divided in to two halves from the equator and that is why at equator water just run down with out truning.

Answer 3

FRrom Wikipedia:
"A popular misconception is that the Coriolis effect determines the direction in which bathtubs or toilets drain, and whether water always drains in one direction in the Northern Hemisphere, and in the other direction in the Southern Hemisphere. In reality, the Coriolis effect is a few orders of magnitude smaller than other random influences on drain direction, such as the geometry of the sink, toilet, or tub; whether it is flat or tilted; and the direction in which water was initially added to it. Note that toilets typically are designed to only flush in one rotation, by having the flush water enter at an angle. If one takes great care to create a flat circular pool of water with a small, smooth drain; to wait for eddies caused by filling it to die down; and to remove the drain from below (or otherwise remove it without introducing new eddies into the water) – then it is possible to observe the influence of the Coriolis effect in the direction of the resulting vortex[citation needed].

This is less of a puzzle once one remembers that the earth revolves once per day but that a bathtub takes only minutes to drain. When the water is being drawn towards the drain, the radius with which it is spinning around it decreases, so its rate of rotation increases from the low background level to a noticeable spin in order to conserve its angular momentum (the same effect as ice skaters bringing their arms in to cause them to spin faster)."

(It was always explained to me as Coriolis effect, but I never did the math!)

Answer 4

Its because of the earth's rotation, and it is dependent on your hemisphere, any where North of the equator will drain counter clockwise, while south will drain clockwise.

Answer 5

No, it's not the coriolis force. The coriolis force is rather weak on small scales; it only exerts a noticeable force on things like hurricanes and such.

The way water swirls down a drain is the result of the geometry of that drain; it's because of the way it is shaped.

Answer 6

They made fun of this on The Simpsons once.... Homer was using a toilet in Australia that turned clockwise and upon return to their home in "Springfield" saluted the toilet for turning counter-clockwise again.

I think that it depends on which Hemisphere you're in. But I thought the Simpson's was a nice anecdote too.

Answer 7

this is one of those sciency questions. You obviously live in the northern hemisphere for the water to go this way, Ifyou lived in the southern hemisphere then it would go the other way. this is all to do with gravitu rotation nad i think mirrors and voodoo come in to it as well

Answer 8

Gravitational pull. If you are in the northern hemisphere( UNITED STATES) it will rotate in the opposite direction than in the Southern Hemisphere (AUSTRALIA).

Answer 9

Two words: Coriolis Force.

Look it up ☺


Doug