Physics - Electrostatics Question with Solution | TestHub

Two identical conducting spheres with negligible volume have$2.1 \mathrm{nC}$and$-0.1 \mathrm{nC}$charges, respectively. They are brought into contact and then separated by a distance of$0.5 \mathrm{m}$. The electrostatic force acting between the spheres is ___$\times {10}^{-9} \mathrm{N}$.
[Given :$4\pi {\epsilon }_0=\frac{1}{9\times {10}^9}$SI unit]