The correct option is A 12√GmR
Given,
Masses of the two particles are m1=m2=m
And radius of the two particles are r1=r2=R
So ,The Gravitational force of attraction between the particles F=G×m×mR2−−−−−−−−(1)
Ans, centripital force F=m×v2R−−−−−−(2)
From given condition (1) and (2)
Gmm(2R)2=mv2R, v=Gm4R=12√GmR
So the speed of the each particle is v=12√GmR