GUARDARE PER LIVELLI: DAI SISTEMI AI COMPONENTI, DALLE PROPRIETÀ MACROSCOPICHE ALLE STRUTTURE MICROSCOPICHE

Modelling Mechanical Wave Propagation: Guidelines and experimentation of a teaching–learning sequence

This paper reports the design process and the experimentation of a teaching-learning sequence about the concept of mechanical wave propagation and the role played by media where waves are propagating. The sequence focuses on the central issue of the relationships between observable phenomena, like macroscopic behaviours of waves, and their interpretation and/or explanation in terms of corpuscular characteristics of media. We describe the design process with respect to the general framework of the Educational Reconstruction Model and the pedagogical tools used. Results of a teaching/learning experiment, involving a sample of 75 high school students, are also reported. Data analysis is mainly…

Video-Analysis of the flight of a model aircraft

A video-analysis software tool has been employed in order to measure the steady-state values of the kinematics variables describing the longitudinal behaviour of a radio-controlled model aircraft during take-off, climbing and gliding. These experimental results have been compared with the theoretical steady-state configurations predicted by the phugoid model for longitudinal flight. A comparison with the parameters and performance of the full-size aircraft has also been outlined.

Video-analysis of flight of a model aircraft

In recent years, many research studies have pointed out that modelling environments, based on Information Technology, can supply effective pedagogical strategies dealing with complex real-world systems and everyday problem solutions. At the same time, physics teachers have discovered that video analysis is a relatively inexpensive and 188 worthwhile method of studying «real world» examples of phenomena. This kind of approach is often adopted to analyze sports physics. The study of physics of aircraft flight can be considered a real-world topic belonging to the everyone’s common experience. For this reason, here, we use a video-analysis software in order to measure the main dynamic variables…

An inquiry based approach to physics teacher Education: the case of found properties

In this paper we describe some results of an approach to Pre-Service Physics Teacher Education whose general aim is to analyze how Problem-Based activities in pre-service teacher education courses can support the understanding of content, the development of inquiry skills and of pedagogical competences, as well as the merging of these in a form of knowledge appropriate for teaching. The experimentation has been performed with a group of non-Italian Trainee Teachers engaged in one-month mobility activities at University of Palermo, in the framework of the EU Project “Move’in Science”, focused in Physics and/or Mathematics Pre-Service Teacher Education. We briefly discuss a Teaching/Learning …

An Inquiry-Based Approach to Physics Teacher Education: the Case of Sound Properties

In this paper we describe some results of an experimentation on Pre-Service Physics Teacher Education performed with a group of non-Italian Trainee Teachers engaged in one-month mobility activities at University of Palermo, in the framework of the EU Project “Move’in Science”. Some preliminary results of the experimentation of a Teaching/Learning Unit about Mechanical Wave propagation are presented, with particular reference to mental models about wave propagation evidenced by Trainee Teachers. Their understanding of the relevance of pupils’ mental model knowledge, in the framework of what a teacher should do to be an “effective” teacher, is also discussed.

Reply to comment on ‘Measuring longitudinal wave speed in solids: two methods and a half’

We provide a short response to Ganci's comment on our paper 'Measuring longitudinal wave speed in solids: two methods and a half'. The reply faces both the problems involved in the comment: the accuracy of experimental methods and pedagogical aspects.

Teachers’ competences about Inquiry Based approaches to the analysis of Thermal Phenomena: implications for an appropriate training

In this paper we present some preliminary results of a course for in-service teacher education held at University of Palermo in the framework of ESTABLISH, an EU FP7 Project aimed at extending the use of Inquiry Based Science Education in secondary level schools across Europe. In particular, we will report results of a survey performed with 15 second level Italian teachers about the ways they approach the analysis of a simple thermal physics situation, their typical conceptions and some aspects of their attitude with respect to methods aimed at performing classroom investigation in the light of the specific operative processes of an IB approach.

PEDAGOGICAL CONTENT KNOWLEDGE DEVELOPMENT AND PRE-SERVICE PHYSICS TEACHER EDUCATION: A CASE STUDY

Abstract. This paper addresses the question of how to develop prospective teachers’ pedagogical content knowledge (PCK) in science teacher education. The main focus is on the knowledge transformation process and on the cognitive strategies used to shift prospective teachers’ explanations within the domain of modelling thermal physical phenomena. This study investigates the development of PCK within a group of 28 pre-service physics teachers during the first semester of their two-year post-graduate teacher education program. It focuses on the central issue of the relationships between observable phenomena, like macroscopic thermal properties of matter and their interpretation and /or explanat…

Measuring longitudinal wave speed in solids: two methods and a half

Three methods to analyse longitudinal wave propagation in metallic rods are discussed. Two of these methods also prove to be useful for measuring the sound propagation speed. The experimental results, as well as some interpretative models built in the context of a workshop on mechanical waves at the Graduate School for Pre-Service Physics Teacher Education, Palermo University, are described. Some considerations about observed modifications in trainee teachers' attitudes to utilizing physics experiments to build pedagogical activities are discussed.

OptimizingthetreatmentofchronichepatitisduetohepatitisCvirus genotypes 2 and 3: a review

A pedagogical flight simulator for longitudinal airplane flight

This article presents a bi-dimensional model of flight and describes the implementation of a flight simulator able to describe the different phases of longitudinal flight of a real airplane. After identifying the relevant physical variables, the equations of motion are written and solved using a numerical integration method. Using computer simulations, flight paths and time evolution of the kinematics variables are analyzed for a complete flight of a light commercial airplane. The simulations take into account and reproduce the basic actions of a pilot to control the flight. The main maneuvers involved in pilotage are also predicted and explained in terms of model parameter variations induc…

Investigating Teacher Pedagogical Content Knowledge Of Scientific Inquiry

This paper analyses the scientific inquiry in the context of modelling physical systems and point out some related teaching/learning strategies. Two relevant points are also discussed: i)- the different representations of scientific inquiry held by a sample of secondary school physics teachers and their competencies in conducting investigations aimed at solving scientific problems; ii)- what kind of supports can be supplied to teachers in order to modify their misconceptions about scientific inquiry and develop adequate competences related to Pedagogical Content Knowledge of Scientific Inquiry. The topic will be analysed in the light of some preliminary results of a course for in-service ph…

ELASTIC WAVES: MENTAL MODELS AND TEACHING/LEARNING SEQUENCES

In last years many research studies have pointed out relevant student difficulties in understanding the physics of mechanical waves. Moreover, it has been reported that these difficulties deal with some fundamental concepts as the role of the medium in wave propagation, the superposition principle and the mathematical description of waves involving the use of functions of two variables. In the context of pre-service courses for teacher preparation a teaching/learning (T/L) sequence based on using simple RTL experiments and interactive simulation environments aimed to show the effect of medium properties on the propagation speed of a wave pulse, has been experimented. Here, preliminary resul…

Collisions and Mechanical Wave Propagation in Elastic Rods

Some results from experiments intended to measure the propagation speed of sound waves produced by collisions between small bodies and metallic rods are analysed. Elementary models of elastic collision and of the reflection and transmission of waves at media boundaries are discussed and tested with experimental data, in the framework of a workshop on mechanical wave propagation that featured at the University of Palermo in a two-year graduate programme for prospective physics teachers and in courses for undergraduate engineering and physics students.

A Problem Based Approach to Elastic Wave Propagation: The Role of Constraints

A problem-based approach to the teaching of mechanical wave propagation, focused on observation and measurement of wave properties in solids and on modelling of these properties, is presented. In particular, some experimental results, originally aimed at measuring the propagation speed of sound waves in metallic rods, are used in order to deepen the role of constraints in mechanical wave propagation. Interpretative models of the results obtained in the laboratory are built and implemented by using a well-known simulation environment. The simulation results are, then, compared with experimental data. The approach has been developed and experimented in the context of a workshop on mechanical …

Heating and Cooling: Designing a Low Energy Home

This unit is aimed at engaging students in designing and building an energy-efficient scale model house through the understanding of relevant concepts of energy flow in thermal systems. It is developed into 4 subunits that analyse the different processes of thermal energy transfer (conduction, convection and radiation). The project intends also to introduce pupils to infrared thermography, thermal imaging and thermograms, i.e. infrared imaging science. The content area of the unit is energy and power in thermal systems. The subunits are suitable for 14-16 year old students while the data analysis and more theoretical parts of the unit are suitable for 16-18 year old students. The estimated …

The elastic body model: a pedagogical approach integrating real time measurements and modelling activities

In this paper, we describe a pedagogical approach to elastic body movement based on measurements of the contact times between a metallic rod and small bodies colliding with it and on modelling of the experimental results by using a microcomputer-based laboratory and simulation tools. The experiments and modelling activities have been built in the context of the laboratory of mechanical wave propagation of the two-year graduate teacher education programme of Palermo’s University. Some considerations about observed modifications in trainee teachers’ attitudes in utilizing experiments and modelling are discussed.

Pedagogical models of surface mechanical wave propagation in various materials

We report on a teaching approach oriented to the understanding of some relevant concepts of wave propagation in solids. It is based on simple experiments involving the propagation of shock mechanical waves in solid slabs of various materials. Methods similar to the generation and propagation of seismic waves are adopted. Educational seismometers, interfaced with computers, are used to detect and visualize the shock waves and to analyse their propagation properties. A qualitative discussion of the results concerning the propagation and the attenuation of the waves allows us to draw basic conclusions about the response of the matter to solicitation impacts and their propagation.

MODELLING THE DISPERSION PROPERTIES OF MASS LINEAR CHAINS: EXPERIMENTS AND SIMULATIONS

We analyze and discuss the results of an experiment with the goal of revealing the phonon-like acoustic dispersion curve. The experimental apparatus consists of a sonometer and an electromagnetic driver connected to a signal generator in order to establish standing waves along a stretched metal string (a guitar string) upon which a set of beads (used normally for fishing) has been fixed. The oscillation amplitude is measured by means of a detector connected to an MBL interface. We detect the resonance frequencies as function of the wave-number and obtain the corresponding dispersion curve. The results show that deviations from linearity occur when the wavelength is comparable with the dista…