Answer:
They would be [tex]r=9.7\,km [/tex] apart
Explanation:
Electric force between two charged objects is:
[tex] F_{e}=k\frac{\mid q_{1}q_{2}\mid}{r^{2}}[/tex] (1)
With q1, q2 the charges of the humans, r the distance between them and k the constant [tex] k=9.0\times10^{9}\,\frac{Nm^{2}}{C^{2}}[/tex], so if we want the electric force between them will be equal to their 600 N weight, we should make W=Fe=600 N on (1):
[tex]600=k\frac{\mid q_{1}q_{2}\mid}{r^{2}} [/tex]
solving for r:
[tex]r^{2}=k\frac{\mid q_{1}q_{2}\mid}{600}[/tex]
[tex] r=\sqrt{k\frac{\mid q_{1}q_{2}\mid}{600}}[/tex]
[tex]r=\sqrt{(9.0\times10^{9})\frac{\mid(-2.5)(2.5)\mid}{600}} =9682 m[/tex]
[tex]r=9.7\,km [/tex]
