A communication probe is placed in a stationary orbit above the equator of a spherical asteroid named Astraea-9. The asteroid has a radius of 150 km and a rotational period of 8.5 hours8.5\text{ hours}8.5 hours. The probe orbits at an altitude of 350 km above the asteroid's surface.
At what linear speed is the probe moving relative to the centre of Astraea-9?
16 m s−116\text{ m s}^{-1}16 m s−1
103 m s−1103\text{ m s}^{-1}103 m s−1
72 m s−172\text{ m s}^{-1}72 m s−1
31 m s−131\text{ m s}^{-1}31 m s−1
