Abstract
We investigate the sliding of objects on an inclined granular surface close to the avalanche threshold. Our experiments show that the stability is driven by the surface deformations. Heavy objects generate footprintlike deformations which stabilize the objects on the slopes. Light objects do not disturb the sandy surfaces and are also stable. For intermediate weights, the deformations of the surface generate a sliding of the objects. The solid friction coefficient does not follow the Amontons-Coulomb laws, but is found minimal for a characteristic pressure. Applications to the locomotion of devices and animals on sandy slopes as a function of their mass are proposed.
- Received 18 May 2016
DOI:https://doi.org/10.1103/PhysRevLett.119.058003
© 2017 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
Friction Means Life or Death for Ants
Published 3 August 2017
Experiments show that the mass of an object determines whether it slides down a sandy slope, which may explain why insect predators called antlions can trap ants in sand pits.
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