posted by Ricky .
help me please? I'm lost...
A small space probe is put into circular orbit about a newly discovered moon of Saturn. The moon's radius is known to be 550km. If the probe orbits at a height of 1500km above the moon's surface and takes 2.0 earth days to make one orbit, determine the moon's mass. consider the total radial distance required to solve this problem.
moon's gravity provides the centripetal force for the orbit
m v^2 / r = G M m / r^2
... v = 2 π (1500 + 550) * 1000 / (48 * 3600)
r = (1500 + 550) * 1000 meters
... G = 6.67E-11
M = v^2 r / G kg