CHARACTERISTICS OF A SLINKY VIA A DISCRETE MODEL
Main Article Content
Abstract
A slinky, which is a soft spring, is vertically suspended under the influence of gravity. When equilibrium is attained, the slinky is released by letting go of the top. Observing the free falling slinky shows that its bottom turns remain completely at rest until the upper turns collide with them. This paper proposes a model that provides a reasonable explanation for the stated effect, as well as the descriptions of several physical characteristics of the slinky, such as the elastic elongation in equilibrium, the position of the center of mass, and the total collapse time. The model is based on fundamental mechanics and basic calculus, which are encapsulated in the first year of college for physics majors. Therefore, the falling slinky problem should be more approachable for a wider community of physics students and enthusiasts.
Keywords
center of mass, free falling, slinky
Article Details
References
Calkin, M. G. (1993). Motion of a falling spring. American Journal of Physics, 61(3), 261-264. https://doi.org/10.1119/1.17301
Cross, R. C., & Wheatland, M. S. (2012). Modeling a falling slinky. American Journal of Physics, 80(12), 1051-1060. https://doi.org/10.1119/1.4750489
Edwards, T. W., & Hultsch, R. A. (1972). Mass Distribution and Frequencies of a Vertical Spring. American Journal of Physics, 40(3), 445-449. https://doi.org/10.1119/1.1986571
Graham, M. (2001). Analysis of Slinky levitation. The Physics Teacher, 39(2), 90-91. https://doi.org/10.1119/1.1355166
Heard, T. C., & Newby, N. D. (1977). Behavior of a soft spring. American Journal of Physics, 45(11), 1102–1106. https://doi.org/10.1119/1.10956
Mak, S. Y. (1987). The static effectiveness mass of a slinky T M . American Journal of Physics, 55(11), 994-997. https://doi.org/10.1119/1.15282
Newburgh, R., & Andes, G. M. (1995). Galileo Redux or, how do nonrigid, extended bodies fall? The Physics Teacher, 33(9), 586-588. https://doi.org/10.1119/1.2344314
Sawicki, M. “Mik.” (2002). Static Elongation of a Suspended SlinkyTM. The Physics Teacher, 40(5), 276-278. https://doi.org/10.1119/1.1516379
Unruh, W. G. (2011). The falling slinky. https://doi.org/10.48550/arXiv.1110.4368
Vanderbei, R. J. (2017). The falling slinky. Mathematical Association of America, 124(1), 24-36. https://doi.org/10.4169/amer.math.monthly.124.1.24