Physics 1 College Level
posted by Devin .
A planet/moon has a mass of 77.89 × 1023 kg and a radius of 7.9 × 106 meters. What is g on the surface to the nearest hundredth of a m/s2?
Once again, not really sure where to go with this. Out of the 10 problems I've only had trouble with this and one other.

the gravitational constant
G =6.67•10⁻¹¹ N•m²/kg²,
mg =GmM/R²,
g =G M/R²=
=6.67•10⁻¹¹•77.89•10²³/(7.9•10⁶)²=
=8.32 m/s²