The radius of earth is about `6400Km` and that of mars is about `3200 km` The mass of the earth is about `10`times the mass of mars. An object weight `200N` on earth 's surface, then its weight on the surface of mars will be:

Options

A. 80N
B. 40 N
C. 20 N
D. 8 N

Answer

A

Explanation

`g=(GM)/(r^(2))implies`
R is reduced to R/2 and the mass of the mars becomes 10 times
`g_("mars")=(4)/(10)g_("earth")` and `W_("mars")=(4)/(10)W_("earth")=80N`