Even though it is difficult to imagine when temperatures are so high here, there are places in the world that are experiencing winter. Take for example Fairbanks, Alaska where a month long, –40 C cold snap is not uncommon for January. At –40 C (the temperature by the way, where the Celsius and Fahrenheit scales meet) the contents of a cup of hot coffee when tossed into the air crystallizes before hitting the ground. The same is not true for a cup of cold coffee. How can that be? Do your best to explain your answer.
Concepts involved:
- heat transfer, (rate of) cooling, temperature difference (advanced concept: Newton’s law of cooling)
