We studied the students' conceptions concerning pressure in fluids and we elaborated a short teaching sequence on the statics of liquids, implemented and evaluated for two years among science students in the first university year. The aim is to study the pressure of a liquid in a static situation in the presence of gravity. We found that, to promote understanding, it is not enough to say what a given quantity has to be, it is also necessary to explore how the state has “come about”. To connect a global and formal reasoning, based on learnt rules or formulae, and a local, causal reasoning, based on what occurs and changes in a given spot of fluid, it is necessary to activate a systemic form of reasoning, based on the interactions between the parts of the fluid and on a transmission of changes that can explain the mechanism which makes it possible to establish a new equilibrium. The teaching sequence makes use of a model of liquids at the mesoscopic level through an analogy with a set of sponge balls, treated first as mechanical entities, then as a model of elements of fluids. The aims and the results of this experimentation are presented and discussed.
Un modèle mésoscopique de liquide pour l'enseignement de la statique des fluides.
BESSON, UGO;
2001-01-01
Abstract
We studied the students' conceptions concerning pressure in fluids and we elaborated a short teaching sequence on the statics of liquids, implemented and evaluated for two years among science students in the first university year. The aim is to study the pressure of a liquid in a static situation in the presence of gravity. We found that, to promote understanding, it is not enough to say what a given quantity has to be, it is also necessary to explore how the state has “come about”. To connect a global and formal reasoning, based on learnt rules or formulae, and a local, causal reasoning, based on what occurs and changes in a given spot of fluid, it is necessary to activate a systemic form of reasoning, based on the interactions between the parts of the fluid and on a transmission of changes that can explain the mechanism which makes it possible to establish a new equilibrium. The teaching sequence makes use of a model of liquids at the mesoscopic level through an analogy with a set of sponge balls, treated first as mechanical entities, then as a model of elements of fluids. The aims and the results of this experimentation are presented and discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
