Using the analogy between thermodynamics and electricity, two new concepts of thermal charge and quantity of thermal charge are introduced. A simple yet explicit definition of entropy is then derived-entropy is the quantity of thermal charge. As a result, quantity of thermal charge (entropy) and quantity of heat (energy) are now clearly…

Single slit diffraction and the thermal expansion of materials are common components of an undergraduate physics course, though these topics are often taught independently in both lectures and laboratory based courses. Higher levels of cognitive domains can be achieved by building on these established topics and combining them into a single…

Why do we need to pour less water in an egg steamer to prepare more eggs to the same degree of 'doneness'? We discuss the physical processes at work in the electric egg steamer and resolve this seeming paradox. We demonstrate that the main heat transfer mechanism from steam to egg is due to latent heat through condensation. This not only explains…

The article describes research work that can help students observe and experimentally research the effects caused by the emission component of the filament current in fluorescent lamps' cathodes. When analysing the work of electronic devices--multi-purpose lamps that use thermionic emission--research usually focuses on the current caused by the…

This work presents the design of an inexpensive electronic system to measure water temperature and generate an experimental data set used to verify the fitting between experimental and theoretical curves of a water-cooling process. The cooling constant is computed with three different theoretical methods to check their efficiency and this approach…

In this paper a well-known experiment is considered that is used to demonstrate some aspects of water boiling. It is shown that the currently popular explanation is wrong and a better explanation is proposed, backed up with experimental data. Variations of the experiment are proposed that can be used for a more in-depth examination of the…

The anomalous thermal expansion of water in the 0 °C-4 °C range is extremely important to life on Earth, but it is normally not presented experimentally in educational settings. This paper presents a simple experiment to explore the anomalous thermal expansion of water in the 0 °C-4 °C range and the heat exchange processes in natural bodies of…

Heat transfer is a phenomenon well known from everyday life. It is intuitively connected to the properties of materials, that is, to the physics concept of thermal conductivity relevant for cooking or maintaining the constant temperature in rooms, even without being familiar to the underlying physics. However, measurement of thermal conductivity…

Watching over a coffee maker in operation, and designing a simple experiment using it, invokes familiar and unfamiliar physical phenomena and techniques involving calorimetry and heat transfer.

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…

This study has proposed a simple method to show the convective heat transfer. The object in this study is an air conditioner (AC) as a simple case of convection. In addition, AC is also easy to find in the class because most classrooms in Indonesia installed AC. Usually, a visualization needs special software (i.e. MatLab or others) and good…

Students hold many alternative conceptions of thermal physics which are very resistant to change. A conceptual change strategy, the thinking frames approach, based on evidence from educational research was used to address commonly held naïve conceptions about heat in a series of thermal physics lessons. Students' gains in conceptual understanding…

After many years of confusion, thermal performance of sleeping bags has now been quantified and unified using expensive test techniques. Based on Newton's law of cooling, we present a simple inexpensive test and model to check manufacturers' claims on the temperature performance of a range of modern sleeping bags.

In this work we discuss the intricacies of a simulation using the MS Excel spreadsheet that allows to study in detail the process of heat transfer between two reservoirs at different temperatures through a conducting rod when heat losses are neglected. The proposed physical model computes the time dependence of the reservoir temperatures and…

Water exhibits a maximum in density at normal pressure at around 4° degree temperature. This paper demonstrates that during cooling, at around 4 °C, the temperature remains constant for a while because of heat exchange associated with convective currents inside the water. Superficial approach implies it as a new anomaly of water, but actually it…