Question

Universal Gravitation question:
(a) A 5.00-kg object is released
1.20 x 10^7 m from the center of the Earth. It moves with what acceleration relative to the Earth? (b) What If? A 2.00 x 10^24 kg object is released 1.20 x 10^7 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.

based on my knowledge, I'm supposed to use g=GM/r^2.

Then why is the second answer 3.70m/s2 ? Since the mass of the object is not taken into account.

Answer 1

What do you get for the mass of the Earth?

Answer 2

the mass of the earth= 5.98x10^24 KG

Answer 3

Yes, you are right. I think you also get 2.77m/s^2.

Answer 4

even for sub-question b)?

Answer 5

As you said, the acceleration does not depend on the mass of object.

Answer 6

cause in the second one.. the mass of the object is comparable to that of the earth.
So even the earth gets a comparable acceleration towards that huge object. Hence when u calculate RELATIVE to earth, the acceleration of that huge object would be larger

Answer 7

what do you mean "relative to the eath" ?

Answer 8

mashy, do you mean the object also accelerates the earth towards it since it's mass is almost the same?