Formazione in rete degli insegnanti di fisica: un esempio

Descrizione di un progetto di ricerca che ha coinvolto sei Universita' italiane, finalizzato a sperimentare l'uso delle Nuove Tecnologie per la formazione in fisica degli insegnanti di scuola secondaria superiore

‘Home made’ model to study the greenhouse effect and global warming

In this paper a simplified two-parameter model of the greenhouse effect on the Earth is developed, starting from the well known two-layer model. It allows both the analysis of the temperatures of the inner planets, by focusing on the role of the greenhouse effect, and a comparison between the temperatures the planets should have in the absence of greenhouse effect and their actual ones. It may also be used to predict the average temperature of the Earth surface in the future, depending on the variations of the concentration of greenhouse gases in the atmosphere due to human activities. This model can promote an elementary understanding of global warming since it allows a simple formalization of the energy balance for the Earth in the stationary condition, in the presence of greenhouse gases. For these reasons it can be introduced in courses for undergraduate physics students and for teacher preparation

Investigating the magnetic interaction with GEOMAG and Tracker video analysis: static equilibrium and anharmonic dynamics

In this paper, we describe how simple experiments realizable by using easily found and low-cost materials allow students to explore quantitatively the magnetic interaction thanks to the help of an Open Source Physics tool, the Tracker Video Analysis software. The static equilibrium of a 'column' of permanents magnets is carefully investigated by working on digital photos, while the anharmonic oscillations of a magnetic bar under the action of gravity and of magnetic repulsion are analysed by using a digital video. A detailed comparison between theoretical expectations and experimental results is discussed. We discuss how the magnetic force falls off with the distance between the permanent magnets following an inverse pth power law. Static and dynamic measurements of the force and of the periods for small amplitude harmonic oscillations yield an experimental value for p ≈ 2. The dynamical system is a good example of an anharmonic oscillator. The experiments need simple and inexpensive material to be realized and address a relevant topic in the physics curriculum; thus, they appear appropriate to be used in high school and undergraduate physics courses