Electrically charged particles

Question

Two stationary electrically charged particles push each other 100 N. One charge is increased 2 times and the other is decreased 4 time. The distance doesn't change. Calculate the interaction force between electrical charges.

Answer 1

Use Coulomb's law: F = k *q1 *q2 / d² , where F is force, q is charger, d is distance, and k is the Coulomb constant.

If one of the charges is doubled, the force is doubled.. If the other charge is doubled, the force is increased by 4X. The 2 effects combine.

The rigorous way to do this kind of problem:

In the equation above, replace q1 with 2q1, and replace q2 with 4q2