Answer:
F = 3.6 10⁶ N
Explanation:
The expression for the electric force is
F = [tex]k \ \frac{q_1 q_2}{r^2}[/tex]
in this case it indicates that the charge q1 is doubled
q₁ = 2 3 10⁻³ C
q₁ = 6 10⁻³ C
let's reduce the magnitudes to the SI system
q₂ = 6 10⁻³ C
r = 0.3 m
let's calculate
F = 9 10⁹ 6 10⁻³ 6 10⁻³ / 0.3²
F = 3.6 10⁶ N