Naked Science Forum

General Science => General Science => Topic started by: paul.fr on 24/08/2007 14:35:13

Title: the coldness of cold drinks
Post by: paul.fr on 24/08/2007 14:35:13

i have a plastic bottle of Dr Pepper and a can of the same drink. Both have been in the fridge since yesterday. why is it that the can not only feels colder to hold, but the liquid also feels colder to drink?

Title: the coldness of cold drinks
Post by: lightarrow on 24/08/2007 15:58:51

Quote from: paul.fr on 24/08/2007 14:35:13

i have a plastic bottle of Dr Pepper and a can of the same drink. Both have been in the fridge since yesterday. why is it that the can not only feels colder to hold, but the liquid also feels colder to drink?

I don't know the answer to the second, but I know the answer to the first: metals conduct heat better than plastic. When you touch a piece of plastic at 0°C (for ex.), your hand immediately heats it up, and you don't feel it very cold. When you touch a piece of metal at 0°C, heat flows continuously from your hand to the metal (and from the metal's surface to the other metal's part or to the drink) and you feel it very cold.

The same principle can explain why some people can walk on live coal: coal's thermal conductivity is very low. Instead of walking on 500°C live coals, ask them to walk on a 90°C aluminum plate!

Title: the coldness of cold drinks
Post by: Karen W. on 24/08/2007 16:41:20

I have noticed that same difference between the plastic bottles and aluminum cans also!