Daily Top Responders
bourder1 Answers:7 (70pts)
jordan stoddard Answers:7 (70pts)
feedmyneed Answers:6 (60pts)
www.kkxxgo.com Answers:5 (50pts)
twilight Answers:1 (10pts)
streamer20 Answers:1 (10pts)
yarinayarsons Answers:1 (10pts) Daily Top Inquirers
joanntrum Questions:2 (10pts)
Candycane Questions:2 (10pts)
sam Questions:1 (5pts)
gadi Questions:1 (5pts)
Shira Questions:1 (5pts)
sal lomanto Questions:1 (5pts)
tracy.thomas@hawkinsisd.org Questions:1 (5pts)Answer A Question
Does the Coriolis effect have anything to do with the way bathtubs and toilets drain?
Asked by infogirl -
Highest Rated Answer
clockwise and anticlockwise is the effect. The effect is different in the two hemospheres
Comments
No. See Wikipedia's info below.
Contrary to popular belief, the Coriolis effect is not a significant determining factor in the rotation of water in toilets or bathtubs.
Draining bathtubs/toilets
A misconception continues to propagate in popular culture, that the Coriolis effect determines the direction in which bathtubs or toilets drain, such that water always drains in one direction in the Northern Hemisphere, and in the other direction in the Southern Hemisphere. Notably, a Simpsons Episode confirms the myth incorrectly, as do several websites. Strangely, many of these websites incorrectly claim that drain water spins clockwise north of the equator, and counterclockwise south of it, which is reversed from direction of spin that would result from the Coriolis force if it were a determining factor.
The Coriolis effect is a few orders of magnitude smaller than various random influences on drain direction, such as the geometry of the sink, toilet, or tub, and the direction in which water was initially added to it. Most toilets flush in only one direction, because the toilet water flows into the bowl at an angle. If water shot into the basin from the opposite direction, the water would spin in the opposite direction.
The Earth rotates once per day but a bathtub takes only minutes (and a toilet only seconds) 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). As shown by Ascher Shapiro in a 1961 educational video (Vorticity, Part 1) , this effect can indeed reveal the influence of the Coriolis force on drain direction, but only under carefully controlled laboratory conditions.


Add Comment