Gravitational Potential Energy

The energy to counteract gravity $E_g=mg(△h)$

Real Gravitational Potential Energy

Reference point $E_g=0$ as $r_1\to \infty$ since that is where $F_G$ = 0

Gravitational Force

$F_G=\frac{GMm}{r^2}$ $r:$ radius of the object $M:$ mass of object being orbitted $m:$ mass of object orbitting $G:$ Universal Gravitational Constant

Gravitational Potential Energy

$E_G=-\frac{GMm}{r}$

It is negative because infinity is reference point. Everytime you raise something up, the distance from infinity get smaller

Accleration Due to Gravity

$g=\frac{GM}{r^2}$