Question

Find the weight of an object at a height of 6400 km above the earth's surface. The weight of the object at the surface of the earth is 20 N and radius of the earth is 6400 km.​

Answer 1

Answer:F = GMm

        R²  

M is the mass of the Earth m is the mass of the object  

R is the radius of the earth =6400km(given)

When  object is kept on surface.

W=F=GMm= 20 N

           R²

When object is lifted to a certain height=R' = R+h = 2R

h = R = 6400 km

Now we have weight of  the object is

W' = F' =  GMm

               (2R)²  

W' = (1/4).(GMm)

                   R²  

=W

 4

Now the weight of the object will be

weight=20

            4

W=5N