Symmetry and conserved quantity of Lagrangians for nonholonomic variable mass system
变质量非完整系统的Lagrange对称性与守恒量

In this paper are study the symmetry of Lagrangians and the conserved quantities for a nonholonomic variable mass system. Firstly, the criterion of the symmetry of Lagrangians for a nonholonomic variable mass system is given. Secondly, the conditions under which there exist a conserved quantity and the form of the conserved quantity, are obtained. Finally, an example is given to illustrate the application of the results.