  We use kinetic theory to model the dynamics of a small Bose condensed cloud
of heavy particles moving through a larger degenerate Fermi gas of light
particles. Varying the Bose-Fermi interaction, we find a crossover between bulk
and surface dominated regimes -- where scattering occurs throughout the Bose
cloud, or solely on the surface. We calculate the damping and frequency shift
of the dipole mode in a harmonic trap as a function of the magnetic field
controlling an inter-species Feshbach resonance. We find excellent agreement
between our stochastic model and the experimental studies of Cs-Li mixtures.
