why dose water spin anti clockwise down the plughole?

Answer 1

It doesn't necessarily. It's a populr misconception that water spins one way in the northern hemisphere and the other way in the southern hemisphere.

It's actaully the shape of the bowl that determines which way the water will flow.

http://www.abc.net.au/science/k2/moments/s1244639.htm
http://www.ucolick.org/~mountain/AAA/answers/physics/ph16.html

Answer 2

Because it does not.

It is a common misconception that the Coriolis effect dictates that it will go down counter-clockwise in the northern hemisphere and clockwise in the south.

The Coriolis applies to the directionality of Hurricanes and ocean currents. It is too weak to have effect on small selections of water such as in domestic plumbing.

Drainage direction is decided by the shape of the bowl, the direction it was filled, and vortices or forces introduced (someone putting their hand in the bowl).

If you had a perfectly symmetrical bowl of water, was able to remove the plug without disturbing the water, and left it for a week withut disturbing it to let it completely settle, then the water would (In theory) simply drop out at a uniform crisp rate.

Interestingly, when most people I know pull out a plug, they pull it slightly to the right, so it goes counter clockwise, but because I pull it to my left (I am left handed), it goes clockwise.

Answer 3

you are able to start up the spin the two way and it would be sustained by potential of momentum of the liquid. The Coriolis rigidity is fairly susceptible incredibly for small diameters (yet very useful in organizing hurricanes 100s of miles for the time of that spin in opposite on opposite components of the equator). That pronounced, an exceptionally super tank replaced into shipped from North united statesa. to South united statesa. that had a drain on the backside to feed the inlet of a centrifugal pump. The pump did no longer perform good (cavitated) through fact 'flow straighteners' on the tank discharge have been designed for the spin of the northern hemisphere incredibly than the southern hemisphere. you're maximum suitable yet different components might fairly override the Coriolis effect.

Answer 4

curt, you are unfair to be so personal and critical of trevor and his answer. In his favour, he included 2 links to sources he has explored.

I have always believed that the coriolis effect (not a force) was the explanation for this and I have seen on tv an experiment (or rather a demonstration of this effect) where a bucket was drained a matter of metres to the north and the south of the equator!

However, it does seem odd that this effect is visible on such a small volume of liquid where the difference in angular momentum must so minute; so I am happy with trevors answer. How about you parker?
Regards
MM

ps. trevor's answer does imply that water will drain in the same direction in both the northern and southern hemisphere using the same container - does he know that this is the case?

Answer 5

contrary to popular belief there is no such thing as the spin of earth effecting the way the water goes down a plug hole, if you go to the equator the water does not go straight down and it doesnt change direction in southern hemisphere, its all down to the fact that the spin is created when you put the water in the bowl and the direction is in effect stored untill you pull the plug. if you leave it a long time there is still a stored spin, i have not tried reversing the spin manually, maybe you should see if spinning the water clockwise will make it go down hole clockwise.

Answer 6

It is the effect of the corriolis forces acting on the water. The water at one side of the bowl has more rotational speed then the other side, because of the slight difference in distance from the Earth's axis of spin.
When the water is forced into the middle of the basin, this velocity difference makes the water rotate, the closer the water is forced together, the faster the spin, much like an ice skater increasing the speed of her spin by drawing her arms close to her body.

Answer 7

it certainly seems to i have just fill and emptied my basin and kithchen sink three times each , tried pulling the plug in different directions each time , same effect, anticlockwise, this is by no means a scientific experiment but consider this, is Coriolis merely a point of perspective, look at a glass clock the hands move clockwise, turn the clock around the hands appear to turn anticlockwise, this is simply a point of view, in the northern hemisphere we are looking down to the equator in the southern we are looking up, it is mans belief in his omnipotence that we see everything from our perspective and not that of the planet

Answer 8

Because that's the way the currents in the sink or the design of the sink got it moving. There is no other reason and in fact sometimes mine goes clockwise and sometimes the other way. If anyone says coriollis, they are a victim of bad science. Here's a refernce that disproves the coriollis myth ...

http://www.snopes.com/science/coriolis.asp

Answer 9

Do you ever get that feeling of deja vu?
What we need is a standard answer for all these damn questions. i.e.
Debunking the Coriolis effect,
Confirming man did land on the moon in 1969,
Kamikaze helmets
Bermuda Triangle
Why is the sky blue?
etc etc

Answer 10

Trevor's an idiot!! It spins counterclockwise because of the Coreolis effect. It is the same effect that causes low pressure systems in the northern hemisphere to rotate counterclockwise.

Basically, fluids and gases flow from high to low pressure. Because the earth is spinning, that direct flow starts to deviate into the counterclockwise spin you see.