  We use the holographic principle to study quark jets with trailing strings in
an expanding plasma that asymptotes Bjorken hydrodynamics. We make use of the
fact that the trailing string is the locus of the light delay in bulk to obtain
the explicit form for quark jets in the expanding plasma. From the trailing
string solution we calculate the drag coefficient of a heavy quark in the
strongly coupled expanding plasma. The energy scaling of the maximum
penetration length of an ultrarelativistic light quark jet using light rays in
bulk is estimated.
