Planet Mars has a mass of 6.4 × 1023 kg, and you have a mass of 5.0 × 101 kg. What force of gravity is exerted between you and Mars, if you are standing on its surface?

2 answers

gotta know the radius of Mars, since

F = GmM/r^2

everything else you have.
The question was missing the radius of Mars which is 3.43 x 10^6 m.

Fg=GMm / r^2
=(6.67 x 10^-11)(6.47 x 10^23)(50) / (3.43 x 10^6)^2
Fg=1.8 x10^2 N