We study shock propagation in a system of initially stationary hard-spheres
that is driven by a continuous injection of particles at the origin. The
disturbance created by the injection of energy spreads radially outwards
through collision between particles. Using scaling arguments, we determine the
exponent characterizing the power law growth of this disturbance in all
dimensions. The scaling functions describing the various physical quantities
are determined using large scale event driven simulations in two and three
dimensions for both the elastic and the inelastic system. The results are shown
to describe well the data from two different experiments on granular systems
that are similarly driven.Comment: 8 pages, 9 figure