Measuring water temperature. Simple. Or not?

Abstract

The paper describes three simple experiments based on contact temperature measurements. Processes that are studied are associated with heating and cooling of water and they can be integrated into regular lessons in the context of (specific) heat capacity, Newtons' cooling law, convection in liquids or temperature conditioned change in liquid density. The goal of the paper is to point out that even simple measurements can become a source of sometimes unexpected results whose interpretation requires a deeper and more comprehensive physical insight.