For pt.I see ibid., vol.2, p.9531 (1990). An interaction model of the motion equation of a domain wall (DW) is used to calculate the DW velocity and hence the internal friction (IF). A magnetomechanical interaction is proposed to explain the dynamic IF and the unique behaviour that the dynamic IF increases with H/ omega . The model shows that the dynamic IF is not caused by relaxation of DWs and is related to the average velocity of moving DWs. Furthermore, a phenomenological model is proposed and a two-term parametrization expression is used to fit the experimental data of the dynamic IF of Fe, and Ni and Permalloy satisfactorily. It is based on the assumption that the superposition of all contributions of magnetic objects (MOS) (a MO is a single equivalent object in terms of the dynamic properties due to correlation between a group of DWs) gives the field dependence of the dynamic IF. Preliminary discussion of the physical meaning of the parameters is given.