  A conformal transformation of a static or stationary spacetime by a time
dependent conformal scale factor ${S(\tau )}^2$ is one of the methods of
producing a cosmological spacetime. Using this knowledge and Brans-Dicke (BD)
field equations, we investigate two time dependent metrics, including
Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime and conformally
transformed Kerr-Newman black hole, and we obtain solutions that allow
different expansion rates for each geometry. These expansion rates depend on
the matter content of the conformally transformed geometry. We state that the
BD scalar field yields accelerated expansion of the conformal spacetime if the
original metric has vacuum geometry, and no acceleration if the original
spacetime has some curvature or matter content in it.
