Explanation:
Given that,
Charge 1, [tex]q_1=-5.45\times 10^{-6}\ C[/tex]
Charge 2, [tex]q_2=4.39\times 10^{-6}\ C[/tex]
Distance between charges, r = 0.0209 m
1. The electric force is given by :
[tex]F=k\dfrac{q_1q_2}{r^2}[/tex]
[tex]F=9\times 10^9\times \dfrac{-5.45\times 10^{-6}\times 4.39\times 10^{-6}}{(0.0209)^2}[/tex]
F = -492.95 N
2. Distance between two identical charges, [tex]r=0.0209\ m[/tex]
Electric force is given by :
[tex]F=\dfrac{kq_3^2}{r^2}[/tex]
[tex]q_3=\sqrt{\dfrac{Fr^2}{k}}[/tex]
[tex]q_3=\sqrt{\dfrac{492.95\times (0.0209)^2}{9\times 10^9}}[/tex]
[tex]q_3=4.89\times 10^{-6}\ C[/tex]
Hence, this is the required solution.
