Physics
posted by Jacky .
Find the magnitude of the gravitational force a 65.4 kg person would experience while standing on the surface of Earth with a mass of 5.98 × 1024 kg and a radius of 6.37 × 106 m. The universal gravitational constant is 6.673 × 10−11 N · m2/kg2.
Answer in units of N

F = G*M*m/R(earth)^2
M = Earth mass
m = person's mass
Just crank out the number.
Since those are the actual earth mass and radius values, the answer must also be M*g = (65.4 kg)(9.81 m/s^2) = 642 N
Both formulas agree.