We investigate the physical mechanisms of satellite disruption in cold dark matter host halos using idealized N-body simulations based on cosmological initial conditions. We show the importance of resonant shocks and resonant torques with the host halo to satellite heating. The resonant shock is a coupling between the motion of the satellite orbit and its phase space. The resonant torque is the coupling between the azimuthal motion of the satellite orbit and its phase space. For a satellite on a circular orbit, the -1:2:2 (ILR-like) resonance dominates and results in continuous satellite mass loss. Using a perturbation theory calculation, we estimate the required number of satellite halo particles for low order resonances and find that more than 100000 particles are required to reproduce the important resonances correctly. When a satellite is on an eccentric orbit, both resonant shock and resonant torque effects heat the satellite. We present an simple algorithm for estimating satellite mass that includes both shock heating and resonant torquing.