The earth has a radius of 6,400 kilometers. a satellite orbits the earth at a distance of 12,800 kilometers from the center of the earth. if the weight of the satellite on earth is 100 kilonewtons, the gravitational force on the satellite in orbit is?
it would be great if you could add a few words of explanation.

By using a universal gravitational force, we can get that . 

For note : r is a distance from center of the earth to the object.

Then, if  is 6.400 km, and if  is 12.800 km,
we can say that  is 

In first equation we can say that :


then in second equation we can say that :
, 
(because  is  )
, 
we can say that : 
so, by plugging first equation into second equation, we can get

For me a person with a phd and who knows what there talking about.i know the chances of a radiation leak is low but if it does the area within a 96.3 mile radius would be unusable because of contamination

Ithink the answer would be a