Rolling Motion and Crumpled Surfaces
©American Journal of Physics
Abstract
We discuss some aspects of a paper which appeared recently in this journal [F. F. Lima, V. M. Oliveira, and M.A.F. Gomes, Am. J. Phys. 61, 421-422, 1993] in which the fractional dimension of rolling crumpled surfaces is measured experimentally. We show that this experiment may not actually be measuring fractal dimension kinematically at all. In addition, we report a variation of their experiment using. nonfractal grooved cylinders. The results indicate that large irregularities on the surface of ''rolling'' objects may lead to errors in the dynamic measurement of the dimension of crumpled surfaces. (C) 1995 American Association of Physics Teachers.