Explanation:
It is given that,
The time period of artificial satellite in a circular orbit of radius R is T. The relation between the time period and the radius is given by :
[tex]T^2\propto R^3[/tex]
The radius of the orbit in which time period is 8T is R'. So, the relation is given by :
[tex](\dfrac{T}{T'})^2=(\dfrac{R}{R'})^3[/tex]
[tex](\dfrac{T}{8T})^2=(\dfrac{R}{R'})^3[/tex]
[tex]\dfrac{1}{64}=(\dfrac{R}{R'})^3[/tex]
[tex]R'=4\times R[/tex]
So, the radius of the orbit in which time period is 8T is 4R. Hence, this is the required solution.