  We develop a method to extract the dissipation for a heavy moving impurity
immersed in superfluid Fermi gases. The drag force is derived analytically. As
a reward, we are able to extract the dynamical structure factor, from which
density excitations of the system is carefully examined. We show that
dissipations through drag force is associated with two types of excitations,
one being single-particle and the other being collective. We map out the
critical velocity for dissipation across the BEC-BCS crossover, consistent with
existing experiments. For a magnetic impurity, we show that the dissipation is
immune to collective excitations. Our study clearly manifests that dissipation
and associated excitations can be controlled by coupling superfluid Fermi gases
with a moving impurity, and paves the way for further exploring intriguing
realm of nonequilibrium phenomena and dissipation dynamics.
