  Dynamical evolution of stellar mass distribution in star clusters is analysed
by considering simultaneously the effects of dynamical friction, stochastic
heating and the gravitational potential due to mass distribution in the
clusters. A simple expression is suggested for the dynamical friction which
adequately describes it in both high and low velocity ranges and the effect of
mass distribution in the cluster on the dynamics of a test mass can be
described by an anharmonic potential. With the help of energy considerations we
describe the dispersions in position and in velocity for stars of different
masses showing how the slowing down and mass segregation of stars evolve in the
cluster. Results are presented with the parameters for the star clusters of our
Galaxy.
