8. Centripetal Forces & Gravitation

Pluto travels in a fairly elliptical orbit around the Sun. At its closest distance of $4.43\times 10^9$ km, its orbital speed is 6.12 km/s. At its farthest, its orbital speed reduces to just 3.71 km/s. How far is it from the Sun at this point (in km)?

A comet is in a highly elliptical orbit around the Sun with a period of 2400 years. If this comet has a mass of approximately $5\times 10^{14}$ kg, what is the total energy of its orbit?