gravitational field strength g is given by :
If we know the mass of planet generating the gravitational field , then we can calculate the gravitational field at any point r distance away from the center of that planet using the equation
if we want to measure the gravitational field strength on the surface of the planet, then radial distance is simply the radius of the planet R.
Hence gravitational field strength is on surface of planet is
Extract from Physics Stage 6 Syllabus © 2017 NSW Education Standards Authority (NESA)