Does hot water really freeze faster than cold water?

AI Thread Summary
The discussion revolves around the claim that hot water can freeze faster than cold water, a phenomenon known as the Mpemba effect. A woman observed this in her home by timing the freezing of ice trays, which her engineer husband dismissed as nonsense. The conversation explores possible explanations, including the rate of heat loss and surface temperature dynamics. It highlights that while hot water may cool faster initially, it still needs to reach freezing temperatures before solidifying. The topic invites further exploration of the Mpemba effect for a comprehensive understanding.
Rocket_guy
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1. A woman informs her engineer husband that "hot water will freeze faster than cold water". He calls this statement nonsense. She answers by saying that she had actually timed the freezing process for ice trays in the home refrigerator and found that the hot water does indeed freeze faster. As a friend, you are asked to settle the argument. Is there a logical explanation for the woman's observation?



2. NONE



3. Is it becoz of the faster rate of heat loss from hot water as compared to cold water? But water freezes after a certain temeprature .. the hot water will first cool to lower temperature as of the cold water then freeze thus taking more time! Or is it that the surface temp. of the hot water will fall faster and thus may seem that the ice was made faster out of the hot water? Any ideas??
 
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What you are referring to is commonly known as the Mpemba effect. I'm referring you to an external FAQ, not because I can't be bothered to answer your question, but the link discusses the topic comprehensively and you'll get a lot more out of it than if I were to type a few words here.

http://math.ucr.edu/home/baez/physics/General/hot_water.html
 
Hey .. thanks .. that was a nice explanation!
 
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