Energy conversion devices such as fuel cells, metal-air batteries, and electrolyzers have been envisaged as possible solutions for cutting down the continuous accumulation of greenhouse gases resulting from the combustion of fossil fuel. The bottleneck reaction for these devices is the oxygen reduction reaction (ORR) occurring at the cathode. The…

We use a validated conceptual multiple-choice survey instrument focusing on thermodynamic processes and the first and second laws of thermodynamics at the level of introductory physics to investigate the problem-property dependence of introductory and advanced student responses to introductory thermodynamics problems after traditional…

Historically, classical thermodynamics was developed during attempts to improve the efficiency of steam engines. Those investigations led to the well-known zeroth, first, and second laws of thermodynamics. Although these laws are presented independently, linkages between the zeroth and second laws have been pointed out in the physics teaching…

What if energy flowed from cold to hot regions? How would thermodynamics be different? We examine such an imagined cold-to-hot world, abbreviated here as a C2H world, and show that the unfamiliar direction of energy flow implies that two thermally interacting objects at different temperatures will not equilibrate. We find that there is no…

Breathing is something we all do, usually without thinking about it. But when viewed through the lens of physics, respiration becomes an example of elementary thermodynamics. As shown here, the lungs can be modeled as a two-stroke heat engine. Breathing thereby provides a novel physics application for life science students, demonstrating the…

The first law of thermodynamics does not forbid heat engines with 100% thermodynamic efficiency; it is the second law of thermodynamics which states that heat engines cannot obtain 100% efficiency. Can the first law ever show this second law result? Yes. We show that the first law alone can show that some heat engines cannot achieve efficiencies…

Teaching and learning introductory thermodynamics has drawn considerable research attention over the last two decades, especially in several disciplines of higher education. Under particular investigation is the First Law of Thermodynamics (FLT), which offers an expression of energy conservation in thermodynamic systems, as the evidence shows that…

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…

The change in enthalpy of a chemical reaction conducted at constant pressure is equal to the heat of the reaction plus the nonexpansion work of the reaction, ?H = qP + w[subscript additional]. After deriving that relationship, most general and physical chemistry textbooks set w[subscript additional] = 0 to arrive at the claim that ?H = qP, and…

This study focuses on designing a laboratory learning program for a high school chemistry course in which students could discover the fundamental principles of Hess's law via stepwise inquiry. By exploring the chemical properties of common desiccants, mainly those that were reactive in water, students were introduced to the exothermic reaction of…

Physical principles are involved in almost any aspect of cooking. Here we analyse the specific process of baking pizzas, deriving in simple terms the baking times for two different situations: for a brick oven in a pizzeria and a modern metallic oven at home. Our study is based on fundamental thermodynamic principles relevant to the cooking…

This work describes a simple experiment to measure the resistor temperature as a function of the applied power and proves that it is an efficient way to introduce some important physical concepts in classroom, including the Joule's first law, hot-spot temperature, thermal resistance, thermal dissipation constant, time constant and the Newton's law…

The article proposes a new research object for a general physics course--the vapour Cartesian diver, designed to study the properties of saturated water vapour. Physics education puts great importance on the study of the saturated vapour state, as it is related to many fundamental laws and theories. For example, the temperature dependence of the…

In this article we reviewed the main concepts of detonative combustion. Concepts of slow and fast combustion, of detonation adiabat are introduced. Landmark works on experimental and semi-empirical detonation study are presented. We reviewed Chapman-Jouguet stationary detonation and spin detonation. Various mathematical model of detonation wave…

Using everyday life examples is proven didactically useful for teaching physics, as it presents effective applications of physical laws. Cooking and food, in particular, serve two useful purposes: on one side, they are able to engage students in the study of physics with familiar examples; on the other side, thanks to the wide range of physical…