2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27021The change of the friction law from a mesoscopic level to a macroscopic level is studied in the spring-block models introduced by Burridge-Knopoff. We find that the Coulomb law is always scale invariant. Other proposed scaling laws are only invariant under certain conditions.}Plain TEX. Figures not includedCondensed Mattertext