  We consider subleading terms in the one-loop Matrix theory potential between
a classical membrane state and a supergraviton. Nontrivial terms arise at order
v/r^8 and v^3/r^8 which are proportional to the angular momentum of the
membrane state. The effective potential for a graviton moving in a boosted
Kerr-type metric is computed and shown to agree precisely with the Matrix
theory calculation at leading order in the long-distance expansion for each
power of the graviton velocity. This result generalizes to arbitrary order; we
show that terms in the membrane-graviton potential corresponding to nth moments
of the membrane stress-energy tensor are reproduced correctly to all orders in
the long-distance expansion by terms of the form F^4 X^n in the one-loop Matrix
theory calculation.
