Given that the mass of each ball is m = 6.8 kg
The distance between them is d = 2r
Here, r is the radius of the ball.
The gravitational force of attraction is
[tex]F=\text{ 6.2}\times10^{-8}\text{ N}[/tex]We have to find the radius of the ball.
The gravitational force formula is
[tex]F=\frac{Gmm}{(2r)^2}[/tex]Here, the universal gravitational constant is
[tex]G=\text{ 6.67}\times10^{-11}Nm^2kg^{-2}[/tex]The radius will be
[tex]\begin{gathered} r=\sqrt[]{\frac{Gmm}{4F}} \\ =\sqrt[]{\frac{6.67\times10^{-11}\times6.8\times6.8}{4\times6.2\times10^{-8}}} \\ =\text{ 0.114 m} \end{gathered}[/tex]Thus, the radius of one of these balls is 0.114 m
