Question

At which height above earth's surface is the value of g same as in 100 km deep mine

Answer 1

Hey mate ^_^

========
Solution:
========

Let the variable 'g' represent the height. 

g = 0 ( 1- 2h/r )....... (1) 

g = 0 ( 1- d/r  )....... (2) 

The variable 'd' represents the depth.

g = 0 ( 1- 2h/r ) - (1) ≡ g = 0 ( 1- d/r )....... (2)  

 2h/r = d/r

 h = d/2 = 100/2 = 50 km 

=============
Answer: 50 km
=============

#Be Brainly❤️

Answer 2

Let height be h
we know that for variation of g with height,
g=g0(1−2hR) −−−−(1)
and for variation in g with depth
g=g0(1−dR)        −−−−−−−(2)

where d is the depth.

according to the question
g0(1−2hR)=g0(1−dR)⇒2hR=dR⇒h=d2=1002=50km