a. Show that T∝r23 for the planets in a solar system where T is the orbital period of a planet and r is the radius of circular orbit of planet about its sun.
b. Outline what is meant by one astronomical unit (1 AU).
c. Pluto is a dwarf planet of the Sun that orbits at a distance of 5.9×109 km from the Sun. Determine, in years, the orbital period of Pluto.
a.