Gravitation

We use gravitational fields to introduce some of the ideas you need for electric and magnetic fields later on.
http://www.physicsclassroom.com/class/circles/Lesson-3/Newton-s-Law-of-Universal-Gravitation
We link the gravitation and centripetal force to derive Kepler’s laws and can use it to measure the mass on objects.
http://www.physicsclassroom.com/class/circles/Lesson-4/Kepler-s-Three-Laws
http://www.schoolphysics.co.uk/age16-19/Mechanics/Gravitation/text/Newtons_law_of_gravitation/index.html
We discussed how we can think of gravity as a distortion of space-time: https://m.youtube.com/watch?v=MTY1Kje0yLg.
We also saw the link between force, field strength, potential, potential energy and drew some diagrams.
http://en.m.wikibooks.org/wiki/A-level_Physics/Forces,_Fields_and_Energy/Gravitational_fields
http://www.xtremepapers.com/revision/a-level/physics/gravitation.php
http://www.studyphysics.ca/2007/20/02_dynamics/30_field_strength.pdf
https://m.youtube.com/watch?v=oZQpC725pcA