How a soup bowl and a coffee cup cool down

Abstract

The cooling of liquid foods held in plates, bowls, or cups is an event encountered several times a day. Here, it is reported a simple practical activity that demonstrates the role played by different heat transfer mechanisms in that process. The experiments can be done even at home with basic kitchenware. The demonstrations show the important role of evaporative cooling in many cases, versus convection and radiation. In this work, the applicability of Newton’s law of cooling is verified, the contributions of the different heat transfer mechanisms are quantified, and values of heat transfer coefficients are estimated. However, the data analyses and the discussions of the results can be adjusted to different audiences.