Acceleration due to Gravity[g] #8211; At the earth s surface, the value of g is found to be 9.8ms<sup>-2</sup> or 32ft s<sup>-2</sup> . Mathematically, [ g = F/m = GMm/R<sup>2</sup>m = GM/R<sup>2</sup>] where, F = Force exerted by the earth on a mass m, M = Mass of the earth, R = Radius of the earth.