A body weighs `700gm` wt on the surface of the earth. How much will it weigh on the surface of a planet whose mass is `1/7` and radius is half that of the earth

Options

A. 200 gm wt
B. 400 gm wt
C. 50 gm wt
D. 300 gm wt

Answer

b

Explanation

`g=(GM)/(R^(2)),`
`g_(1)=(GM//7)/(R^(2)//4)=(4g)/(7)=(4)/(7)g=700xx(4)/(7)=400`