Question

find the weight of the atmosphere around the earth(take the radius of earth as 6400km)

Answer 1

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