  We provide the exact time-dependent cosmological solutions in the
Randall-Sundrum (RS) setup with bulk matter, which may be smoothly connected to
the static RS metric. In the static limit of the extra dimension, the solutions
are reduced to the standard Friedmann equations. In view of our solutions, we
also propose an explanation for how the extra dimension is stabilized in spite
of a flat modulus potential at the classical level.
