You drop two rocks. one rock has a mass of 8kg and the other a mass of 7kg. The 8kg rock falls no faster than the 7kg rock for what reason. is it due to force of gravity for both being the same?

The gravitational force is significantly constant.

Explanation:

The gravitational force is expressed as:

F = G*M*m/d^2

G = Gravitational constant

M = in this case it is the mass of the planet

m = mass of the rock

d = distance of the rocks from the ground (suppose both at the same height for better comparison)

At the same time, we know that the force that each rock experiences is equal to the product of the mass due to acceleration:

F=m*a

We can match both expressions for F:

G*M*m/d^2 = m*a

we simplify m, and we obtain that the acceleration is independent of the mass of the attracted bodies:

a = G*M/d^2