STUDYING OF INERTIA MOMENT AND POSITION OF mass CENTER OF RIGID BODY OF asymmetric shape in the course of general physics

Traditional methods of teaching general physics in high schools is limited to the study of the inertia moment and position of the mass center of a rigid body symmetrical with respect to its center of mass. However, with a simple physical model it is easy to show that it is possible to study the inertia moment of a body of arbitrary shape experimentally in a university laboratory. Thus, adopted by the traditional methods of teaching general physics constraints associated with difficulties performing theoretical calculations of the inertia moment and position of the mass center of bodies of arbitrary shape. The authors propose a simple method of constructing bodies asymmetrical about the mass center shape, for which inertia moments can be explored first-year students of technical university, both experimentally and theoretically. To do this, each body should take the shape of a rectangular prism, the base of which the straight lines drawn from the origin of the coordinate system can be divided into 3-4 fragment having the shape of right triangle or circle sectors. For these bodies developed a method of study dependence of the inertia moment of the position of the rotation axis. The technique, which has been described in the article, the authors realized and implemented in the educational process as a computer laboratory work, which is called “The moment of inertia of a rigid body”. This work allows you to study with one of the 20 rectangular prisms of asymmetrical with respect of their mass centers. In this work, students record the rotation period with the help of the virtual stopwatch, calculate inertia moment of the prism at different positions of the rotation axis, define position (coordinates) of the mass center and inertia moment relative an axis through the mass center for it, compare the results and forecast received earlier. Analysis of experience of using this work in the laboratory practicum of the general physics course suggests that the proposed technique and the method of constructing bodies asymmetrical shapes can be used as the basis for the creation of a new natural laboratory work, which will expand the capabilities of traditional laboratory practicum at technical university.

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