Hello! I'm having some problems with a question that my professor has given me. Below is the question. I have already figured out the planet's orbital and angular-orbital velocities, but included that part due to the fact that some information was included. PICA-9 and PIC-10 are planets orbiting its star, PIC-2A. Find each of the planet's orbital and angular-orbital velocity if PIC-2A has the same mass as our Sun, PICA-9 is 1.0 A.U. away from the star and PICA-10 is 5.5 times further than PICA-9. What are the gravitational potential energies of each planet with respect to the star? 2. Relevant equations Since everything must be in m/kg form, I have figured out that: Distance from PICA-9 and PICA-2A is 1.50X1011m Distance from PICA-10 and PICA-2A is 8.22X1011m PICA-2A mass is 1.989X1030kg G=6.67X10-11 3. The attempt at a solution Since the formula for GPE given to me is -GMm/r (G=gravity in space, M="the anchor" mass, m=orbiting object's mass, and r=the distance between the planets), I wasn't sure if PE=mgh would be a helpful formula in this case. Would finding the kinetic energy be helpful as well? How would I find the mass of the planets? Thanks for reading!