body of weight is inversely propotional to square of its distance from center of earth,radius of the earth is 6380 km, how much 80 kg man weigh 1600 km from the surface of earth

2 answers

80*(6380/7980)^2 = 51
kg is mass, which does not change. The weight would become the weight of a 51kg man.
w=k/d^2 where (d,W)=(6380,80)

80=k/(6380)^2
k=80*40704400
k=3256352000

Now as the radius is 6380 km and the body is up 1600 km , d=7980 km

w=k/d^2
w= 3256352000/(7980)^2
w=51.13 kg