2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/28350A large class of classical dynamical systems with an external rapidly oscillating driving action is considered and the effective Hamiltonian-like equations for the mean motion are obtained. The respective Liouville equation for the distribution function of the mean coordinates and momenta is derived.minor misprints corrected; 4 pages, no figures, REVTeXStatistical Mechanicstext