(b) [6] For a more realistic case in which the comet experiencesgravitational forces, consider a comet approaching Earth. Estimatethe distance from the Earth (in Earth radii) at which Earth’sgravity begins to be as important as, or more important than, thatof the Sun. Neglect the Moon’s gravity. Discuss the effect of theMoon’s gravity.
ps: i already have answer for part a but for more background onthe question, part a is listed below
a.Suppose that a comet,5km in diameter,is moving directlytowards Earth at a constant speed of 10km/s. On one night (callthis t = 0), its angular diameter subtends an angle of 2arcseconds. Assuming that its speed remains constant, how long willit take before its angular diameter subtends an angle of 2arcminutes? Note that by assuming the comet moves at a constantspeed, this problem explicitly neglects any gravitationalforces.
