Modelling the Earth as a symmetric, spherical body (and by using the law of gravitation), we come up with the equation $$w = F_g = \frac{Gm_Em}{R_E^2}$$ How do we arrive to the equation to get the acceleration due to gravity at the earth's surface? $$g = \frac{GM_E}{R_E^2}$$ Where:
- $G = \text{gravitational constant} = 6.67\times10^{-11}\ \mathrm{N}$
- $M_E = \text{mass of Earth} = 5.98\times10^{24}\ \mathrm{kg}$
- $R_E = \text{Earth's radius} = 6380\ \mathrm{km}$
One thing I know of is the fact that we use Newton's second law, but how?