Would a metal coffee mug keep liquids hotter longer or let it cool quicker?
Answer Hello Karen, Metal is a better heat conductor than porcelain, the latter being quite a good thermal insulator. So a massive metal mug would conduct the heat to the outside much faster. But there are metal mugs that are made of aluminium, which has a lower heat conductance than most other metals, and which have an inner and an outer wall, with an air-space between them. These mugs use the same principle as a thermos can. Since air is a very bad heat conductor, the contents retains its temperature (hot or cold) much longer. The cooling depends on the exact material and design properties of the mugs concerend. Why not conduct an experiment: Fill the same amount of hot water into the two cups you want to compare and compare the temperature after fixed time intervals, say after five minutes, after 10 minutes and after 15 minutes. For a comparison your index fingers are a fine instrument 🙂 Just make sure your hands are accustomed to the same temperature – e.g. hold them both in your
