

Distance of satellite from the surface of the earth is given to be 3 times its radius
Now, including the radius of the earth, the satellite is at a distance of 4 times the radius of the earth from the centre of the earth
T2 is proportional to r3
Under normal condition for existing satellite close to the surface of the earth, T1 is proportional to r13/2
For the other satellite which is 4 times away from the radius of the earth, T2 is proportional to r23/2
Let the radius of the earth be r
T1 = k r13/2
60 = k r3/2 ----------------------Eqn (1)
Hence, substituting the condition that the satellite is at a distance of 4 times the radius of the earth, we get
T2 = k (4r)3/2 ----------------------Eqn (2)
Eqn (1) / Eqn (2) is 60/T2 = 1/ (4)3/2 which is 1/ 4√4 =1/ 4 * 2 = 1/8
Hence, new time period is T2 = 60 * 8 = 480 minutes
