Question

Two point charges are brought closer together, increasing the force between them by a factor of 25. By what factor was their separation decreased? In other words, if r1 is the original separation and r2 is the final separation, what is the ratio r1/r2?

Answer 1

Answer: 1/5

Explanation: The force between the two charge is inversely proportional to the square distance between charges so as the force increased a factor of 25 the distance can reduced divided by a factor of 5.