Question

define acceleration due to gravity show that gravity decreases with the depth​

Answer 1

Acceleration gained by an object due to the graviaitonal force is known as acceleration due to gravity.

It is maximum at the surface and decreases with depth because, on the surface of the earth, gravitational force is being applied to you only from below. As you go deeper, masses from all around you start pulling you to all directions. These forces cancel out and the total force that is acting on you will be lower as compared to the surface.

FYI,

At the centre of the earth, acceleration due to gravity would be 0.

Answer 2

it is a defined as rate of change of velocity.