A comet moves about the Sun in a highly elliptical orbit. At perihelion its distance from the Sun is 0.60AU and at aphelion it is 35.0AU.
(a) Find the semi-major axis of the comet’s orbit.
(b) Determine the orbital period of the comet in Earth years.
(c) Assuming a circular orbit of radius equal to the semi-major axis obtained in part (a), calculate the comet’s average orbital speed in kms−1. Use 1AU=1.5×108km and π=3.14.
(d) Compare this speed with Earth’s orbital speed by finding the ratio vcomet/vEarth to two significant figures.