  We explore the energy dynamics of a two dimensional (2D) harmonically trapped
Bose-Einstein condensate inside a box potential, excited by a moving
red-detuned laser potential (RDLP). For an RDLP velocity $v$ less than a
critical value $v_c$, energy oscillations are observed to begin simultaneously
with the motion of the RDLP. For $v > v_c$, these oscillations are delayed
through a transient in the energy. At the end of the delay time $t_{ons}$, the
energy oscillations are regenerated again, and $t_{ons}$ is found to depend on
$v$ through universal relations for two cases: one for an RDLP depth sufficient
to break off a BEC fragment, another for a depth insufficient to split the BEC.
In the case of splitting, $t_{ons}$ exactly equals the time it takes the BEC
fragment (dragged by the RDLP trough) to reach the hard wall of the box
potential.
