The height of the point vertically above the earth's surface, at which acceleration due to gravtiy becomes 1% of its value at the surface is (Radius of the earth =R)

Options

A. 8 R
B. 9 R
C. 10 R
D. 20 R

Answer

b

Explanation

`(g_(h))/(g)=((R)/(R+h))^(2)`
`(1)/(100)=((R)/(R+h))^(2)`
`R+h=10R`
`h=9R`.