## Pathare (2015)

This research paper reports the success of a module of five activities designed to develop undergraduate students’ understanding of thermal equilibrium. These activities were designed to be incremental and develop the use of a liquid flow analogy. The research was carried out by a university-based researcher in India.

#### Evidence-based suggestions

• Linking the concepts of temperature and thermal equilibrium through a demonstration of zero net heat flow makes it easier for students to understand these concepts.
• Illustrating thermal equilibrium in terms of zero net heat flow can be achieved by analogy with hydrostatic equilibrium (being understood as a state with zero net flow).

#### Learners’ ideas

• Many students predicted incorrectly that two objects made of different materials submerged in a heat bath would equilibrate to different temperatures.
• Some students predict that an 'insulating' material brought into thermal contact with a heat bath will not change its temperature at all.
• Some students predict that objects of different sizes or shapes brought into thermal contact with a heat bath will equilibrate to different temperatures (i.e. different to that of the heat bath and to each other).
• Most students could correctly predict that a heated object brought into thermal contact with a heat bath would reach an equilibrium temperature between the initial temperatures of the bath and the object.

#### Further suggestions

• Illustrating to students the parameters on which an object's approach to thermal equilibrium depends can help students understand the concept.
• The use of hydrostatic equilibrium as an analogy for thermal equilibrium can help students make predictions about the behaviour of objects brought into contact.

### Study Structure

#### Aims

The research aimed to design and develop a module of activities to improve students' understanding of thermal equilibrium.

#### Evidence collection

Qualitative answers given by students in predict-observe-explain situations were analysed across the course of five incremental activities, followed by interviews with 10 of the 112 students.

Students were asked to use POE (predict, observe, explain) on five activities designed by the researchers. Their answers to successive activities were analysed through a simple comparison of the number of students able to describe scenarios correctly before and after the course.

#### Details of the sample

The sample consisted of 112 students (aged 19-20 years) who had undergone a basic thermodynamics course in the first year of their undergraduate study. The sample was selected by convenience.