8. A comet with unknown mass mc is in an elliptical orbit around the sun: R. Rp mc mc MS ū When the comet is at its parahelion R, it has a speed of up = 80km/s and at its aphelion R, it has a speed of va = 10km/s. For this problem suppose we do not know the mass of the sun M, or the value of Newton’s constant G, but we can approximate the orbit of the earth around the sun as a circle with radius 1.5 x 108 km and the speed of the earth around the sun as 30kms. What is the parahelion Rp and aphelion Ra of the comet? You can ignore any effect the gravity of the earth might have on the comet.