"two point charges exert a 6.50 n force on each other. what will the force (in n) become if the distance between them is increased by a factor of 8? "

0.102N

Explanation:

According to Coulomb law, the charge force between 2 points charge is directly proportional to the product of the charges and inversely proportional to the square of distance between the point charges. This means if the distance between them is increased by a factor of 8, then the charge force must be decreased by a factor of 8*8 = 64.

So the new charge force F = 6.5 / 64 = 0.102 N