Coulomb's Law for Two Charged Spheres

Introduction

In 1767, British natural philosopher Joseph Priestley became the first scientist to propose that electrical force followed an inverse-square law, similar to Newton's law of universal gravitation. However, he did not elaborate on this. The general law was enunciated by French physicist Charles Augustin de Coulomb. In 1784, Coulomb used two charged spheres arranged in a torsion balance to verify that the interaction forces varied as the inverse square of the distance between their centers.

Objectives

In this activity, you will

• Use a simple apparatus along with video analysis to explore the inverse square law proposed by Coulomb.