Answer:
1. Reduce the charge on second object by half or
2. Increase the distance between the two charges by a factor of 1.41 (√2).
Explanation:
Lets assume,
Charge on first object = Q
Charge on second object = q
Distance between them = r
Force between the two charges = F
According to Coulomb's law,
![F = k \frac{Qq}{r^{2}}](https://tex.z-dn.net/?f=F%20%3D%20k%20%5Cfrac%7BQq%7D%7Br%5E%7B2%7D%7D)
where, k = Coulomb constant
New value of charge on first object = 2Q. Thus the new force(F') will be
![F' = k \frac{2Qq}{r^{2}}](https://tex.z-dn.net/?f=F%27%20%3D%20k%20%5Cfrac%7B2Qq%7D%7Br%5E%7B2%7D%7D)
![F' = 2F](https://tex.z-dn.net/?f=F%27%20%3D%202F)
So, to bring the value of force(F') to original value, there are two options:
1. Reduce the charge on second object by half or
2. Increase the distance between the two charges by a factor of 1.41 (√2).