Question

Why is acceleration due to gravity of earth independent of mass?

Answer 1

$F=\frac{GMm}{r^2}$
where G is the gravitational constant, r is in this case the distance between the centre of the Earth and the object the gravitational force is acting on, and most importantly, M and m are the mass of the Earth and the mass of the object, respectively.

Of course, as well as this, F = mg

Thus, F = mg = $\frac{GMm}{r^2}$ and this can be rearranged to find
$g=\frac{GM}{r^2}$

It can be observed from this that the mass of the object cancels out, so it is of no consequence to the acceleration it undergoes as a result of gravity.