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

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

To find out the weight of an 80 kg man 1600 km from the surface of the Earth, we can use the inverse square law.

The inverse square law states that the force of gravity between two objects is inversely proportional to the square of the distance between their centers. In this case, we can assume that the man is at a distance of 1600 km from the Earth's surface, which means the distance between the man and the Earth's center would be the sum of the radius of the Earth (6380 km) and the distance from the surface (1600 km).

Let's calculate the new distance from the center of the Earth:
Distance from center = Radius of the Earth + Distance from the surface
Distance from center = 6380 km + 1600 km
Distance from center = 7980 km

Now, we can use the inverse square law formula to find the weight:

Weight = (Weight on the surface of the Earth) * (Distance from surface of the Earth / Distance from center of the Earth)^2

Weight = (80 kg) * (6380 km / 7980 km)^2

Weight = (80 kg) * (0.8)^2

Weight = (80 kg) * 0.64

Weight = 51.2 kg

Therefore, the weight of an 80 kg man 1600 km from the surface of the Earth is approximately 51.2 kg.