Question

A planet orbits a sun in a clockwise elliptical orbit as shown in the diagram below

Bubble in the letter representing the position or choose e if it is constant

At which position does the planet have the greatest gravitational energy?

Answer 1

Greatest gravitational energy is at "C".

The planet has to do work "against" the field to get to "C".

Also, if m v R (angular momentum) is constant then as R increases v must decrease for this term to be constant and KE = 1/2 M v^2 must decrease also to get to point C.