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 g wt
B. 400 g wt
C. 50 g wt
D. 300 g wt

Answer

B

Explanation

`W_E=0.7xx9,8N=700` gwt
`g.=(GM.)/(R.^2)=(GxxM/7)/((R//2)^2)=4/7g=4/7xx9.8`
`W_P=400gwt`