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

Answer

B

Explanation

`g_h = (gR^2)/((R + h)^2) " given , " g_h = (g)/(100)`
`therefore (gR^2)/((R + h)^2) = (g)/(100) " or " R + h = 10 R " or " h =98`