Bozeman: Calculating the gravitational force
Bozeman: Gravitaional Field Strength
Practice questions from Khan Academy:
Gravitational field strength
Comparing gravitational and inertial mass
Gravity and Orbits
Answers here
Worked solutions here
Gravitational potential
Orbital mechanics
Introductory problems: Gravitational potential
Introductory problems: Orbits
Focus on the distinction between V and GPE. Think about the units and what they mean.
Consider when you can use Ep = mgh and when you need to use Ep = GMm/r