Rolling friction on a granular medium.
We present experimental results for the rolling of spheres on a granular bed. We use two sets of glass and steel spheres with varying diameters and a high-speed camera to follow the motion of the spheres. Despite the complex phenomena occurring during the rolling, the results show a friction coefficient nearly independent of the velocity (0.45-0.5 for glass and 0.6-0.65 for steel). It is found that for a given sphere density, the large spheres reach a longer distance, a result that may also help explain the rock sorting along natural stone accumulations at the foot of mountain slopes.
De Blasio
Fabio Vittorio
FV
Department of Geosciences, University of Oslo, P.O. Box 1047 Blindern, 0316 Oslo, Norway.
Saeter
May-Britt
MB