L. Borghi

How to teach friction: Experiments and models

Students generally have difficulty understanding friction and its associated phenomena. High school and introductory college-level physics courses usually do not give the topic the attention it deserves. We have designed a sequence for teaching about friction between solids based on a didactic reconstruction of the relevant physics, as well as research findings about student conceptions. The sequence begins with demonstrations that illustrate different types of friction. Experiments are subsequently performed to motivate students to obtain quantitative relations in the form of phenomenological laws. To help students understand the mechanisms producing friction, models illustrating the processes taking place on the surface of bodies in contact are proposed.

Physics Education in Science Training of Primary School Teachers

Summary Our experience in physics training of primary school teachers is briefly presented together with a project we prepared for the teaching of science in primary school. We suggest for training teachers a practicum‐based strategy which requires that they initially carry out experimental activities designed for their pupils and express their ideas and needs. Usually they meet difficulties similar to those revealed by children and ask to explore in more detail the topics tackled in the laboratory activity. The aim of the proposed approach is to help teachers understand basic physics concepts and realise the importance of taking into account the pupils’ conceptions in the teaching process.

A Three‐Dimensional Approach and Open Source Structure for the Design and Experimentation of Teaching‐Learning Sequences: The case of friction

We have developed a teaching‐learning sequence (TLS) on friction based on a preliminary study involving three dimensions: an analysis of didactic research on the topic, an overview of usual approaches, and a critical analysis of the subject, considered also in its historical development. We found that mostly the usual presentations do not take into account the complexity of friction as it emerges from scientific research, may reinforce some inaccurate students’ conceptions, and favour a limited vision of friction phenomena. The TLS we propose begins by considering a wide range of friction phenomena to favour an initial motivation and a broader view of the topic and then develops a path of interrelated observations, experiments, and theoretical aspects. It proposes the use of structural models, involving visual representations and stimulating intuition, aimed at helping students build mental models of friction mechanisms. To facilitate the reproducibility in school contexts, the sequence is designed as an open source structure, with a core of contents, conceptual correlations and methodological choices, and a cloud of elements that can be re‐designed by teachers. The sequence has been tested in teacher education and in upper secondary school, and has shown positive results in overcoming student difficulties and stimulating richer reasoning based on the structural models we suggested. The proposed path has modified the teachers’ view of the topic, producing a motivation to change their traditional presentations. The open structure of the sequence has facilitated its implementation by teachers in school in coherence with the rationale of the proposal.

Knowledge of air: A study of children aged between 6 and 8 years

The research presented here was carried out jointly by physicists and psychologists with the purpose of verifying whether participation in physical experiments together with social interaction (with adults and school‐mates) can favour childrens development of causal knowledge and their understanding of a physically complex problem. Children aged between 6 and 8 years were involved in a study of air and its properties. Tests show that exposing children of this age to a sequence of appropriate experiments which are carried out together with their class‐mates, leads them to give up pre‐causal explanations and to resort to physical ones.

Computer Simulation and Laboratory Work in the Teaching of Mechanics

By analysing the measures of student success in learning the fundamentals of physics in conjunction with the research reported in the literature one can conclude that it is difficult or undergraduates as well as high-school students to gain a reasonable understanding of elementary mechanics. Considerable effort has been devoted to identifying those factors which might prevent mechanics being successfully learnt and also to developing instructional methods which could improve its teaching (Champagne et al. 1984, Hewson 1985, McDermott 1983, Saltiel and Malgrange 1980, Whitaker 1983, White 1983). Starting from these research results and drawing from their own experience (Borghi et al. 1984, 1985), they arrived at the following conclusions. A strategy based on experimental activity, performed by the students themselves, together with a proper use of computer simulations, could well improve the learning of mechanics and enhance the interest in, and understanding of, topics which are difficult to treat in a traditional way. The authors describe the strategy they have designed to help high school students to learn mechanics and report how they have applied this strategy to their particular topic of projectile motion.

Microscopic models for bridging electrostatics and currents

A teaching sequence based on the use of microscopic models to link electrostatic phenomena with direct currents is presented. The sequence, devised for high school students, was designed after initial work carried out with student teachers attending a school of specialization for teaching physics at high school, at the University of Pavia. The results obtained with them are briefly presented, because they directed our steps for the development of the teaching sequence. For both the design of the experiments and their interpretation, we drew inspiration from the original works of Alessandro Volta; in addition, a structural model based on the particular role of electrons as elementary charges both in electrostatic phenomena and in currents was proposed. The teaching sequence starts from experiments on charging objects by rubbing and by induction, and engages students in constructing microscopic models to interpret their observations. By using these models and by closely examining the ideas of tension and capacitance, the students acknowledge that a charging (or discharging) process is due to the motion of electrons that, albeit for short time intervals, represent a current. Finally, they are made to see that the same happens in transients of direct current circuits.

Computers in physics education: An example dealing with collision phenomena

This paper describes an interactive graphics package for teaching and learning collision phenomena which includes analysis of one‐dimensional elastic collisions, two‐dimensional elastic collisions, and inelastic collisions. The package is intended as a support for a traditional course for first‐year physics students.

Un modèle pour la compréhension des propriétés des liquides

In this paper a proposal aimed at favouring the understanding of fundamentals of hydrostatics, with particular attention to the Pascal principle, is presented. The instruction material was developed in a hypertextual environment and based on a model which explains staticproperties ofliquids. Particularattention is given to the isotropic transmission of forces inside a liquid and to its action on the walls of the container. The model, with appropriate adjustements, can lead to define pressure.

Integrated computer simulations and the physics laboratory: a unit dealing with wave propagation

Abstract The work we present is part of a national project aimed at introducing the study of computer science in Italian schools and at favouring its use in the study of different curricular disciplines. Our research, dealing with the teaching of Physics, has resulted in a unit based on a close link between experiments and computer simulations. The topic we have chosen is wave propagation. We propose a simple model to illustrate how wave propagation originates and a computer based strategy to introduce the subject in high school.

Teaching mechanical oscillations using an integrated curriculum

Abstract A set of teaching materials dealing with harmonic oscillations was developed as part of a research project investigating the influence of different pedagogical tools on physics learning. The materials incorporate simulation software and laboratory activities associated with Teacher and Student Units. The project involved research groups at seven Italian universities and the materials have been trialled in high schools nation‐wide. This paper describes the experimental protocol for the use of these materials in pilot classes and the evaluation of student learning and teacher training results. The intervention was found to improve physics education at school praxis level and to promote understanding of the content area as well as appreciation of the role of experiments and simulations in the construction of scientific knowledge