Two manned satellites approaching one another at a relative speed of 0.450 m/s intend to dock. The first has a
mass of 4.00 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity (in m/s)? Adopt the reference frame in which the second satellite is initially at rest and assume that the positive direction is directed from the second satellite towards the first satellite.