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. 100 gram wt
B. 200 gram wt
C. 300 gram wt
D. 400 gram wt

Answer

D

Explanation

`g=(GM)/(R^(2))" " therefore g_(P)=(G xx (M)/(7))/((R//2)^(2))=(4)/(7)(GM)/(R^(2))=(4)/(7)(g)`
`therefore` Weight `= mg = 700 xx (4)/(7)=400` gr. wt.