Many have heard the "old wives tale" stating that if you put hot water into a freezer, it freezes in less time than it would have if it had been cold to start. Never did I believe such a claim, as it runs contrary to one of the basic laws of nature.

While surfing one day on sites illustrating "bad science" I actually found a plausible real life reason why this in fact can be true (read:not always true, but possible). Running this experiment under controlled conditions [eg. measure the same volumes of hot and cold water, make sure containers are equal in any relevant aspect (shape, material, conductance properties, covered or not etc.), and that the freezer is properly set to achieve a uniform temperature throughout], can you come up with a reasonable set of conditions for which the water in the hot container would freeze before the water in the cold container?

diferent masses of water, becose the hot water is (moast often) less dense than the cold water. the heat extracted is the product betwen the mass and the caloric quoeficient. The power of the freezer is a constant and it is the product of the energy(heat) it extracts and the 1/time it takes to do so.

Conclusion: if you take the same volumes of cold and hot water, the mass of the cold water will be (in genere) biger, will have a bigger quantity of heat(energy) and the freezer will take more time to cool it down

Posted by vije on 2004-07-03 05:15:37