General, restricted and misleading forms of the First law of thermodynamics

Abstract

The stored energy E and the internal energy U of a system are different. Delta E = Q - W is defined here as the general form, and Delta U = Q - W as the restricted form, of the First law equation. Forms involving Delta Q and Delta W are misleading. It is argued that the work done by a system on the surroundings should be taken as a positive quantity, in line with several, but not all, A-level syllabuses. Greater emphasis should be given to non-equilibrium processes in physics syllabuses.

Overcoming students’ misconceptions concerning thermal physics with the aid of hints and peer interaction during a lecture course

“…After receiving conventional teaching at the start of the intervention, the students still possessed a variety of misconceptions. For instance, problems were observed with the process quantities of heat and work [3,6,16,17,19,20], use of the first law of thermodynamics [17], microscopic models [7,13], and thermal processes [6,13,16].…”

“…One crucial finding is students' tendency to consider these to be state quantities [3,6,16,17] or to be independent of process, including the idea that work and heat equal zero in a cyclic process [17]. Furthermore, problems with signs of work and heat seem to be relatively common among students [16,19,20]. It should also be acknowledged that students frequently produce erroneous microscopic explanations.…”

Chemical energy in an introductory physics course for the life sciences

“…33 However, the situations are biological, dealing with temperature regulation in mammals and other animals and leveraging students' knowledge of physiology (e.g. the difference between mammals, which maintain a constant internal temperature, and animals whose body temperatures depend on external conditions; the effects of metabolic reactions on thermal and chemical energy), and students are explicitly asked to separately analyze changes in thermal energy and chemical energy.…”

Can Definitions Contribute to Alternative Conceptions?: A Meta-Study Approach

“…There can be disagreement on how these words should be defined, and their meanings can differ for some scientists. For example, temperature could be defined in term of heat, but heat may be defined as substance (Newburgh, 2009), motion (de Berg, 2008 and interaction (Moore, 1993) or others. The conception of temperature may vary with students if their conception of heat is different.…”