m-ICTE2006m-ICTE2006

Didactic strategies using Didactic strategies using simulations for Physics simulations for Physics

teaching teaching

S. ConcariS. Concari11, S. Giorgi, S. Giorgi11, C. Cámara, C. Cámara11 and N. Giacosa and N. Giacosa22

11  Facultad de Ingeniería Química, Universidad Nacional del Litoral, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santa Fe, ArgentineSanta Fe, Argentine

22  Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones, Posadas, Misiones, Argentinede Misiones, Posadas, Misiones, Argentine

sconcari@fiqus.unl.edu.arsconcari@fiqus.unl.edu.ar

Paper made within the projects:Paper made within the projects:

Didactic strategies of physics teaching for Didactic strategies of physics teaching for the articulation pre-college level/Polimodal the articulation pre-college level/Polimodal and universityand university ( (PICT 04 -13646 – UNL CAI+D PICT 04 -13646 – UNL CAI+D 2005 / PI 06-31)2005 / PI 06-31)

Relationship between models utilised in Relationship between models utilised in Physics teaching at college level, students Physics teaching at college level, students mental representations and scientific mental representations and scientific conceptual modelsconceptual models (PIP CONICET 03080 - (PIP CONICET 03080 - UNL CAI+D 2005 / PI 06-32)UNL CAI+D 2005 / PI 06-32)

Didactic strategies for Physics Didactic strategies for Physics teachingteaching

Real Real experiences or LAB workexperiences or LAB work

Computer simulationsComputer simulations programmes previously installed programmes previously installed ““fislets“ (Physics and appletfislets“ (Physics and applet) that run ) that run

on lineon line

Pencil and paper problem solving (PS)Pencil and paper problem solving (PS)

In this paper we describe computer simulations In this paper we describe computer simulations integrated with LAB work and with PS. integrated with LAB work and with PS. The proposal was designed for mechanics, The proposal was designed for mechanics, optics, electricity and contemporary Physics optics, electricity and contemporary Physics teaching. teaching. These activities are developed in basic Physics These activities are developed in basic Physics courses for Engineering and Sciences students courses for Engineering and Sciences students in Argentine universities. in Argentine universities. The activities are aimed to promote a critical The activities are aimed to promote a critical analysis of the models involved in solving simple analysis of the models involved in solving simple problems, the comparison of the results derived problems, the comparison of the results derived from a qualitative analysis of the problems, with from a qualitative analysis of the problems, with those ones obtained from the simulations, and those ones obtained from the simulations, and with experimental results.with experimental results.

Examples of simulations Examples of simulations 1. 1. MechanicsMechanics

Programme Fall of Spherical Particles (FSP): Programme Fall of Spherical Particles (FSP): www.fiqus.unl.edu.ar/galileo/download/software/fluidwww.fiqus.unl.edu.ar/galileo/download/software/fluidos.zipos.zipFSP allows students to simulate the falling FSP allows students to simulate the falling movement of different spherical bodies in movement of different spherical bodies in vacuum, in the air, and in liquids. The activities vacuum, in the air, and in liquids. The activities help students to understand phenomena such as help students to understand phenomena such as fog atmospheric dust and clouds “floating”.fog atmospheric dust and clouds “floating”.As a real experience the students study a small As a real experience the students study a small sphere falling in a viscous liquid, such as an oil sphere falling in a viscous liquid, such as an oil or glycerine. Using the Stokes formula they or glycerine. Using the Stokes formula they obtain the viscous coefficient of the liquid. obtain the viscous coefficient of the liquid.

Screen of the programme FSPScreen of the programme FSP

2. Optics2. Optics

We use a virtual optics bank available in: We use a virtual optics bank available in: http://webphysics.davidson.edu/alumni/MiLee/jahttp://webphysics.davidson.edu/alumni/MiLee/java/ob_mj12.htmva/ob_mj12.htm The students are expected to design an The students are expected to design an experience that allows them to reproduce experience that allows them to reproduce experimentally a compound microscope. experimentally a compound microscope. The The didactic sequence includes the determination of didactic sequence includes the determination of the focal distances of the convergent lenses, the the focal distances of the convergent lenses, the assembling of centred optics systems and the assembling of centred optics systems and the theoretical revision of the basis of the compound theoretical revision of the basis of the compound microscope. microscope.

Screen simulating the formation of images in Screen simulating the formation of images in

a compound microscopea compound microscope

3. 3. Continuous current circuitsContinuous current circuits The free software used is Crocodile Clips (Croco): The free software used is Crocodile Clips (Croco): www.crocodile-clips.comwww.crocodile-clips.comCroco allows users to simulate continuous current circuits. Croco allows users to simulate continuous current circuits. The simulations are presented as problems. One of the The simulations are presented as problems. One of the problems consists in connecting a generator to a lamp problems consists in connecting a generator to a lamp -situation (a)- then adding to the circuit another equal lamp in -situation (a)- then adding to the circuit another equal lamp in series with the initial one -situation (b)-. In a first stage it is series with the initial one -situation (b)-. In a first stage it is asked to analyze and justify theoretically the values of the asked to analyze and justify theoretically the values of the current intensity in both situations, and then to verify the current intensity in both situations, and then to verify the answers with the software Croco.answers with the software Croco.Another activity for discussing the limitations of the model Another activity for discussing the limitations of the model involved in Croco consists in connecting directly (only in the involved in Croco consists in connecting directly (only in the simulation) a LED to a 9 V bat. and registering the values of simulation) a LED to a 9 V bat. and registering the values of intensity and power (given by the software). We find absurdly intensity and power (given by the software). We find absurdly high values without the accusation of any deterioration of the high values without the accusation of any deterioration of the LED in the software, something that would surely happen in LED in the software, something that would surely happen in practice.practice.

Screen of Screen of Crocodile ClipsCrocodile Clips

4. 4. Contemporary PhysicsContemporary Physics

The Albert programme developed by M. Wullenweber The Albert programme developed by M. Wullenweber (ChessBase GmbH Hamburg) was selected to introduce (ChessBase GmbH Hamburg) was selected to introduce the hypothesis, models, equations and mathematical the hypothesis, models, equations and mathematical procedures which allow students to solve quantum procedures which allow students to solve quantum Physics problems. Physics problems. Albert allows the students to simulate the density of Albert allows the students to simulate the density of probability in terms of the wave function for a free probability in terms of the wave function for a free particle, and for a particle subjected to a potential well or particle, and for a particle subjected to a potential well or barrier. barrier. For the experimental measuring of the Planck constant For the experimental measuring of the Planck constant we select an experience that requires the use of we select an experience that requires the use of unsophisticated equipment and materials of low cost (unsophisticated equipment and materials of low cost (G. G. Brizuela and A. Juan, Am. J. Physics, Brizuela and A. Juan, Am. J. Physics, 6464 819 1996) 819 1996)

Albert screen with a potential barrier (blue) Albert screen with a potential barrier (blue) and the wave packet from the left (red)and the wave packet from the left (red)

ConclusionsConclusions

The pencil and paper SP, the lab work and the The pencil and paper SP, the lab work and the simulations make up didactic resources of great simulations make up didactic resources of great potentiality for the students, who are not always potentiality for the students, who are not always conscious neither of the modelling they make, nor of the conscious neither of the modelling they make, nor of the validity and scope of the models they use. The validity and scope of the models they use. The promotion of these basic capacities would facilitate the promotion of these basic capacities would facilitate the development of indispensable competences for their development of indispensable competences for their future professional practice.future professional practice.The simulation programmes allow the professor to make The simulation programmes allow the professor to make his own didactic design, including not only the qualitative his own didactic design, including not only the qualitative observation of the phenomena but also the solving of observation of the phenomena but also the solving of quantitative problems. To perform this task they would quantitative problems. To perform this task they would know not only the Physics contents but also the models know not only the Physics contents but also the models involved in the computation simulations they used. involved in the computation simulations they used.