PhysicsCode 9702
Gravitational force between point masses
What this topic asks you to be able to do
- appreciate that a uniform sphere's mass can be treated as a point mass located at its centre, when the point under consideration lies outside the sphere
- recall Newton’s law of gravitation, F = Gm1m2 /r², and apply it to the force acting between two point masses
- analyse circular orbits in a gravitational field by treating the gravitational force as the cause of the centripetal acceleration
- understand that a geostationary satellite keeps the same position above the Earth’s surface: it orbits once every 24 hours, travelling west to east directly over the Equator