We use the Landau-Lifshitz equations to construct a dynamic model for describing a system of interacting particles. The dynamic model will produce results different from the static model for a finite line of particles with weak interaction strength and parallel anisotropy axes at a large angle to the line. Small two and three dimensional clusters of particles are also discussed. All the results indicate that increasing the angular distribution of the particles will reduce the difference between the static and dynamic simulations. The dynamic switching model is necessary for perpendicular recording because of the alignment of the switching units in the perpendicular media.