Answer:
Since there is attraction force between two charges so the other charge must be - 3C
Explanation:
As we know that the force between two charges is given by formula
[tex]F = \frac{kq_1q_2}{r^2}[/tex]
here we know that
[tex]F = 4.23 \times 10^{13}N[/tex]
also we know that
[tex]q_1 = 10C[/tex]
r = 8 cm
now we have
[tex]4.23 \times 10^{13} = \frac{(9\times 10^9)(10)q}{0.08^2}[/tex]
so we have
[tex]q = -3C[/tex]