gravitational potential at a point as the work done in bringing unit mass from infinity to the point; gravitational potential is zero at infinity

gravitational potential \(V_g = -\dfrac{GM}{r} \) at a distance r from a point mass M; changes in gravitational potential

force–distance graph for a point or spherical mass; work done is area under graph

gravitational potential energy \(E = mV_g = -\dfrac{GMm}{r} \) at a distance r from a point mass M

escape velocity.