Anisotropia e heterogeneidade do atrito seco entre superfícies : um estudo experimental com aplicação no ensino médio

Abstract

Experimental activities have played an important role in the learning process in teaching science in recent years, especially in physics teaching. This work consists of an investigative study on the coefficient of friction with classes of students of basic education, specifically students of the middle level. This investigation consisted in the assembly of an experiment from the construction of a mobile platform on an inclined plane. The friction phenomena were studied taking into account the anisotropy of the surfaces in contact between blocks the different material (mdf, wood and acrylic) and the platform. The work was applied at the José Lins de Figueirêdo School of the public network of the municipality of Altinho-PE, with students of the three years of high school. We used the methodology of teaching by investigation, where the topics on friction were approached theoretically. After that, we did the research through the experimental activities. The analyzes of the results with the students were all qualitative, addressing the theme and discussing the results of the phenomena in the classroom. These analyzes were divided in two experiments: in the first, we find the critical angle of slip for each orthotropic angle of the platform; in the second, the distances traveled by the different blocks on the platform were analyzed after the equilibrium had been disturbed by an external impact in each of the previous experiments. The results obtained were satisfactory and showed that the coefficient of static friction between the surfaces of the materials used has different characteristics as a function of the preferential direction of movement, evidencing the anisotropy and heterogeneity of this magnitude.