Question

Why does acceleration due to gravity goes on decreasing as we go to the centre of the earth

Answer 1

We know that g = GM/r²

When we go inside the earth, towards the centre, the r decreases, Hence, r² would also decease. Thus, the acceleration due to gravity should increase as it is inversely proportional. But this is not the case.

When we move towards the centre of earth, the mass of earth above is excluded. Hence, the mass required for g decreases, so the value of g also decreases.