Answer:
(a) burnout speed at apogee in the external tank disposal orbit=7.82 km/sec
(b) ΔV required for the OMS-1 =0.066 km/sec
(c) ΔV required for the OMS-2 =0.045 km/sec
(d) This part of the question is explained in detailed way in the attached file.
Explanation:
Detailed explanation of all the parts of the question are given in attached files.