Coulomb's law: When two point charges are 2.0 cm apart, each one experiences a 1.0-N electric force due to the other charge. If they are moved to a new separation of 8.0 cm, the electric force on each of them is closest to
A) 1.0 N.
B) 4.0 N.
C) 16 N.
D) 0.25 N.
E) 0.063 N.

Question

Quizplus · Accepted Answer

Coulomb's law states that the electric force between two point charges is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them. When the distance is increased from 2.0 cm to 8.0 cm, the distance is quadrupled. Since the force varies inversely with the square of the distance, the new force is 1/16th of the original force. Therefore, if the original force was 1.0 N, the new force is 1.0 N / 16 = 0.0625 N, which is closest to 0.063 N.

Coulomb's Law: When Two Point Charges Are 2