Answer:
F' = 800 N
Explanation:
The electrical force between charges is 400 N.
The electrical force between two charges is given by :
[tex]F=k\dfrac{q_1q_2}{r^2}[/tex]
If q₁' = 2q₁, new force becomes,
[tex]F'=k\dfrac{q_1'q_2'}{r^2}\\\\F'=k\dfrac{2q_1\times q_2}{r^2}\\\\F'=2\times F\\\\F'=2\times 400\\\\F'=800\ N[/tex]
So, the new force becomes 800 N.