At what height above the surface of the earth will the acceleration due to gravity be 25%of its value on - Physics - Gravitation

Question

At what height above the surface of the earth will the acceleration
due to gravity be 25%of its value on the surface of the
earth?assume that the radius of the earth is 6400km

Varsha · Accepted Answer

g'=25/100g
R=6400 km
g'/g=R2/(R+h)2

[(25/100)g/g]1/2=R/(R+h)

5/10=R/(R+h)
2R = R+h
R=h
so, h=6400 km

At what height above the surface of the earth will the acceleration due to gravity be 25%of its value on the surface of the earth?assume that the radius of the earth is 6400km.