Putting a wet paper towel around a can and placing it in the freezer can cool it relatively quickly due to a combination of factors:
Evaporation: When the wet paper towel is exposed to the dry, cold air inside the freezer, the water on the towel begins to evaporate. Evaporation is a process that requires energy, and it draws heat away from the can, causing it to cool down. The water molecules in the towel gain energy from the surrounding environment, lowering the temperature of the can.
Conductive cooling: The wet paper towel acts as a conductor of cold. The moisture on the towel comes into direct contact with the can, which allows for efficient heat transfer. As a result, the cold temperature of the towel is effectively transferred to the can, further cooling it down.
Insulation: The wet paper towel also acts as an insulating layer around the can. While it conducts cold to the can, it also helps to trap the cold air inside, preventing warmer air from reaching the can and slowing down the warming process. The insulation helps to maintain a lower temperature around the can for a longer period.
By utilizing these mechanisms, the wet paper towel enhances the cooling process by facilitating evaporation, efficient heat transfer, and insulation, which collectively contribute to the rapid cooling of the can in the freezer.