Archimedes' principle is one of the foundation subjects in physics. Normally the principle is exemplified by reference to floating boats. However, Archimedes' principle also applies to objects embedded in waterlogged ground, which can lead to the surprising result of an object weighing several tons being lifted. A practical example is presented of…

We report on the study of student difficulties regarding a heat engine in the context of a Stirling cycle by the method of measurement. An in-class test about a Stirling engine with a regenerator was taken by three classes, and the students were asked to perform one of the most basic activities--calculate the efficiency of the heat engine. Our…