Question

Problem 1: Suppose you wanted to increase the force between two point charges by a factor of 5. 

By what factor must you change the distance between them? 

Answer 1

Answer 2

SOLUTION :

F is inversely proportional to  squared distance.

=> F = k / d^2 

So,

F1 = k  / (d1)^2 

F2 = k  / (d2)^2

=> F2/F1 = 5 = (d1)^2 / (d2)^2 

=> d2/d1 = sqrt(F1 / F2) = sqrt(1 / 5) = 0.4472 

=> d2 = 0.4472 d1 

Hence distance between the charges to be reduced to 0.4472 times the initial distance. (ANSWER).