  We apply the general results of the kinetic theory of systems with long-range
interactions to particular systems of physical interest. We consider repulsive
and attractive power-law potentials of interaction r^{-\gamma} with \gamma<d in
a space of dimension d. For \gamma>\gamma_c= (d-1)/2, strong collisions must be
taken into account and the evolution of the system is governed by the Boltzmann
equation or by a modified Landau equation; for \gamma<\gamma_c, strong
collisions are negligible and the evolution of the system is governed by the
Lenard-Balescu equation. In the marginal case \gamma=\gamma_c, we can use the
Landau equation (with appropriately justified cut-offs) as a relevant
approximation of the Boltzmann and Lenard-Balescu equations. The divergence at
small scales that appears in the original Landau equation is regularized by the
effect of strong collisions. In the case of repulsive interactions with a
neutralizing background (e.g. plasmas), the divergence at large scales that
appears in the original Landau equation is regularized by collective effects
accounting for Debye shielding. In the case of attractive interactions (e.g.
gravity), it is regularized by the spatial inhomogeneity of the system and its
finite extent. We provide explicit analytical expressions of the diffusion and
friction coefficients, and of the relaxation time, depending on the value of
the exponent \gamma and on the dimension of space d. We treat in a unified
framework the case of Coulombian plasmas and stellar systems in various
dimensions of space, and the case of the attractive and repulsive HMF models.
