CONSERVATVE QUANTITIES AND LIE'S SYMMETRIES OF NONCONSERVATIVE DYNAMICAL SYSTEMS

This paper discusses Lie’s symmetry of nonconservative mechanical sys-tems. The existence conditions of conservative quantities corresponding with Lie's symmetryare est ablished. Two illustrative examples are given. Finally, we explain from an examplethat Noether's symmetry may not be Lie's symmetry for nonconservative mechanical system.