Naked Science Forum
On the Lighter Side => Science Experiments => Topic started by: ATremor on 09/01/2010 00:50:59
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It is an experiment I remember seeing in school. You add a couple of tablespoons of water to an aluminum can. You heat the can on the stove until the water is boiling. While the can is simmering you get another sauce pan full of cool water and keep it near by. When the water is boiling in the can, you then use a tongs and quickly turn it the can upside down into the cool sauce pan. The can is immediately crushed! What is happening exactly?
AT
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http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/steam-powered-can-crusher/
"As you heat the can to 100°C the water inside starts to boil, turning into steam and increasing in volume by a factor of about 600 times. This steam pushes out, or displaces, most of the air in the can.
When you put the can into the cold water the sides of the can cool down rapidly, which allows the steam to condense on the sides of the can. This happens much too rapidly for the water to rush in through the mouth of the can and fill the space, so the pressure decreases inside the can and the external air pressure crushes the can."
Does that help?
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Yup sure does! Thanks!
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what is the law that explains this phenomenon? the ideal gas law? the combined gas law? or is there some other force acting upon this can? plase helpppp
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The reduction in pressure, so volume is to do with a phase change - going from gas to liquid. Ideal gasses don't liquify so their laws won't help you. There are lots of equations to do with phase changes, but they are more complex, and involve more experimentally determined constants than I think you are looking for.