An inquiry-based laboratory on friction
Department of Physical Sciences, Earth and Environment, University of Siena,Siena, ItalyAbstract – date of last change of the paper: 06.10.2013Sliding friction is usually introduced in high school, but rarely through activities inlaboratory. A qualitative introduction to friction is presented by proposing exploration ofdifferent kind of materials in order to suggest which aspects can be relevant and whichinteraction is involved. Different quantitative experiments are proposed for studyingLeonardo's laws for friction. The learning path was tested with two high school classesduring an instruction trip at department. Students were engaged in the inquiry-basedintroductory activity and seemed to realize with care the measurements. However, theanalysis of their reports shows some learning difficulties.Keywords: Secondary education: upper (ages 15-19), f riction, active learning in laboratoryIntroductionFriction is a complex phenomenon, usually missing in high school laboratory.Nevertheless, sliding friction is often introduced in the easier way in mechanics because ofsimple exercises which can be proposed on this subject. Another important aspect rarelyexplored in laboratory at school is the relation between static and kinetic friction.Furthermore, a closer look in this topic allows to introduce interesting discussions on thestructure of matter, relations between macroscopic and microscopic modelling, whichaspects of a phenomenon are really relevant, which others can be omitted and for whichreason, and so on. Last but not least, it can be the starting point for introducing students tonanoscience world.Inspired by a recent study in higher education [1, 2], a learning path designed for highschool students is presented. The starting point was a qualitative explorative path onfriction designed for stimulating discussion in a workshop in which physics teachers andstudents were attending. The unexpected reactions, especially from teachers, induced me toa wider investigation [3] in order to improve the learning on this topic both in secondaryschool and in higher education.The activity was realized within the Italian National Plan for Science Degrees [4-5].National Plan for Science DegreesThe decline of interest in studying science is a serious concern. In recent decades it hasbeen detected almost everywhere a consistent decrease of graduates in science disciplines.In order to reverse this trend in Italy, the Ministry of Education and Scientific Researchpromoted in 2005 a wide national project (P rogetto nazionale per le Lauree Scientifiche,i.e. PLS) [ 4].The main actions of PLS were professional development for teachers and orienting forstudents essentially by means of laboratory activities. In 2009 it was launched the NationalPlan for Science Degree (sa me acronym PLS) where some of the most effectivemethodological aspects were emphasized in new guidelines [4, 5] focused on: