The height above the surface of earth at which the gravitational filed intensity is reduced to `1%` of its value on the surface of earth is

Options

A. `100 R_(e)`
B. `10 R_(e)`
C. `99 R_(e)`
D. `9 R_(e)`

Answer

D

Explanation

`E prop (1)/(r^(2))`
`(E_(2))/(E_(1)) = ((r_(1))/(r_(2)))^(2)`
or `(1)/(100) = ((R_(e))/(R_(e) + h)) ^(2)`
or `h = 9 R_(e)`