Question

find the altitude for which the acceleration due to gravity is 25% of that at the surface of the earth (Radius of earth = 6400km)​

Answer 1

Answer:

Explanation:Force on the body placed on Earth's surface is

F=

R

2

GMm

​

But, F=mg hence,

mg=

R

2

GMm

​

where, variables have their usual meanings.

gR

2

=GM

Now, force on the body at geo-potential height say h (altitude) where the acceleration due to gravity is 25% of that at the earth's surface i.e.

100

25g

​

=

4g

​

Hence, we can write

4

g

​

=

(R+h)

2

GM

​

4

g

​

=

(R+h)

2

gR

2

​

(R+h)

2

=4R

2

Taking roots for both sides we get

R+h=2R

h=R

Answer 2

Answer:

hope it helped you ....