Question

Explain the variation of g with depth from the earth's surface

Answer 1

Answer:

So to understand the variation of gravity (g) with respect to depth , you need to have the concept of reduced mass.

When we are considering depth "d" below the Earth surface only that mass enclosed shall cause a force of gravity at that point.

This assumption is based on Gauss's law

Gauss's law on electrostatics having analogy in Gravitation.

So , you need to find the enclosed mass at the depth "d" .

It is obtained by

[{(Total mass)/(Total volume)}* new volume ]

Once the enclosed mass is obtained use the general method of finding the gravitational acceleration.

Now, refer to the attached photo to understand better.

Finally as a conclusion, "g" decreases with increase in depth.