PLAYING WITH A CHAIN OR PHYSICAL AND MATHEMATICAL INFORMATICS
Abstract
The article describes an educational laboratory work within the framework of interdisciplinary connections at the intersection of informatics, mathematics and physics: the study of the sagging of a closed chain with different support points. A technology of computer processing of photos and videos of a physical experiment with the subsequent processing of the media files on the computer is illustrated. We present the π chain number (1.258... − the optimal ratio of the chain length to the distance between its attachment points) and its relation to the previously unexplored problem of the shape of the sag of a closed chain hanging on two nails. The analytic expression for this constant was first found. A new physical and mathematical constant is found − the critical angle of the sagging of a closed chain on the "hangers". The problem of the sagging of a closed chain on a cone is detailed. The applicability of the computer tool "optimization with constraints" for solving problems of theoretical mechanics is investigated. Three main tools of mathematical computer tools are described: numerical mathematics, symbolic mathematics and graphics. The importance of using units of measurement when solving physical problems on a computer is emphasized. The problem of publishing mathematical formulas in articles and books is discussed.
References
[2] Merkin D.R. Introduction to the mechanics of a flexible thread. M.: Science, 1980. 240 p. (In Russian)
[3] Ochkov V.F., Ochkova N.A. A project of a monument to three mathematicians or MathMetry. Cloud of Science. 2017; 4(4):548-571. Available at: https://elibrary.ru/item.asp?id=32603280 (accessed 15.04.2018). (In Russian)
[4] Ochkov V.F., Lener F., Chudova Yu.V., Kapitonets V.K., Tarakanova D.Yu. Physics vs informatics: rope polygon with weights in static, kinematics and dynamics Or Newton vs Lagrange. Cloud of Science. 2017; 4(2):303-336. Available at: https://elibrary.ru/item.asp?id=29461211 (accessed 15.04.2018). (In Russian)
[5] Ochkov V.F., Bogomolova E.P., Ivanov D.A. Physical and mathematical studies with Mathcad and the Internet. Second edition. SPb: Publishing house "Lan", 2018. 560 p. (In Russian)
[6] Wang C.Y. The optimum spanning catenary cable. European Journal of Physics. 2015; 36(2). DOI: 10.1088/0143-0807/36/2/028001
[7] Zubelevich O.E., Samsonov V.A. Chain on the cone. Collection of scientific and methodical articles "Theoretical mechanics". Issue 30. Publishing house of Moscow State University. 2018, pp. 131-138 (In Russian)
[8] Ochkov V.F., Kolhepp F. Physic and IT: centre of gravity of a black box. Informatics in school. 2017; 7(130):65-70. (In Russian)
[9] Ochkov V.F., Bogomolova E.P. Teaching Mathematics with Mathematical Software. Journal of Humanistic Mathematics. 2015; 5(1):265-285. DOI: 10.5642/jhummath.201501.15.
[10] Solodov A., Ochkov V. Differential Models. An Introduction with Mathcad. Springer-Verlag Berlin Heidelberg, 2005. 232 p. DOI: 10.1007/b138129
[11] Korobov V., Ochkov V. Chemical Kinetics with Mathcad and Maple. Springer-Verlag Wien, 2011. 344 p. DOI: 10.1007/978-3-7091-0531-3
[12] Behroozi F. A fresh look at the catenary. European Journal of Physics. 2014; 35(5). DOI: 10.1088/0143-0807/35/5/055007
[13] Wang C.Y., Watson L.T. The elastic catenary. International Journal of Mechanical Sciences. 1982; 24(6):349-357. DOI: 10.1016/0020-7403(82)90068-6
[14] Chen J.-S., Li H.-C., Ro W.-C. Slip-through of a heavy elastica on point supports. International Journal of Solids and Structures. 2010; 47(2):261-268. DOI: 10.1016/j.ijsolstr.2009.09.031
[15] Boresi A.P., Schmidt R.J. Engineering Mechanics – Statics. Baker & Taylor Books, North Carolina. 2000. 704 p.
[16] Christensen H.D. Analysis of simply supported elastic beam columns with large deflections. Journal of Aerospace Science. 1962; 29:1112–1121.
[17] Lippmann H., Mahrenholtz O., Johnson W. The heavy elastic strips at large deflections. International Journal of Mechanical Sciences. 1961; 2:294–310.
[18] Parbery R.D. The effect of stiffness on the shape of the elastic catenary. Civil Engineering Transaction. 1976; 18:98–101.
[19] Wang C.Y. A critical review of the heavy elastica. International Journal of Mechanical Sciences. 1986; 28(8):549–559. DOI: 10.1016/0020-7403(86)90052-4

This work is licensed under a Creative Commons Attribution 4.0 International License.
Publication policy of the journal is based on traditional ethical principles of the Russian scientific periodicals and is built in terms of ethical norms of editors and publishers work stated in Code of Conduct and Best Practice Guidelines for Journal Editors and Code of Conduct for Journal Publishers, developed by the Committee on Publication Ethics (COPE). In the course of publishing editorial board of the journal is led by international rules for copyright protection, statutory regulations of the Russian Federation as well as international standards of publishing.
Authors publishing articles in this journal agree to the following: They retain copyright and grant the journal right of first publication of the work, which is automatically licensed under the Creative Commons Attribution License (CC BY license). Users can use, reuse and build upon the material published in this journal provided that such uses are fully attributed.