  We study fragmentation numerically using a simple model in which an object is
taken to be a set of particles that interact pairwisely via a Lennard-Jones
potential while the effect of the fragmentation-induced forces is represented
by some initial velocities assigned to the particles. The motion of the
particles, which is given by Newton's laws, is followed by molecular dynamics
calculations. As time evolves, the particles form clusters which are identified
as fragments. The steady-state cumulative distribution of the fragment masses
is studied and found to have an effective power-law region. The power-law
exponent increases with the energy given to the particles by the
fragmentation-induced forces. This result is confirmed by experiments.
