acceleration relative to earth?

Question

(a) A 6.00 kg object is released 4.8e7 m from the center of the Earth. It moves with what acceleration relative to the Earth? Assume that the objects behave as pairs of particles, isolated from the rest of the Universe.

For that question, my answer is 0.17m/s^2, which is correct but i'm confused about the second part:

(b) A 2.00 e24 kg object is released 4.8 e7 m from the center of the Earth. It moves with what acceleration relative to the Earth?

* I assumed that the mass of the object does not matter when using the equation

g = GM(earth)/R^2

but the assumption is wrong. They do not have the same acceleration relative to Earth although they're released from the same R. Any hints or help please?

Answer 1

In the first case, the acceleration of the Earth is negligible.

In the second case, the acceleration of the Earth towards the object must also be considered.

Answer 2

I worked the problems and came up with identical accelerations for both objects -- 1.7^ minus 7 m/sec/sec