electrostatic forces   Concepts covered: Introduction to Electrostatic | Coulomb Theory Introduction Electrostatic was known even since the time of ancient Greeks that amber rubbed with fur would become electrified attract other objects. Benjamin Franklin had also developed the concept of electrostatic since he is the one who found two kinds of charges, positive and negative but at that time Franklin was not able to determine the value of the forces between the two charges. It was Charles Augustin Coulomb, a French scientist, who first quantitatively measured the electrical attraction and repulsion between charged objects and established that the force was proportional to the product of the charges and inversely proportional to the square of the distance between them. Electrostatic can be divided into two categories, Electrostatic Discharge (ESD) and Electrostatic Attraction (ESA). The force acts in a direction along the straight line connecting the two charges, and the force is repulsive when q1and q2are both positive or both negative, corresponding to a positive value ofq1q2. The force is attractive when the charges have opposite sign so that q1q2 is negative. Thequantity å0, called the permittivity constant, is equal to 8.854 × 10-12 coulomb2/(newton-meter2),and assures that the force will be in newtons when the charge is expressed in coulombs. Coulomb Theory Coulomb Theory is a law that defines the relationship of forces between two separated points. Coulomb force can be calculated with the formula F= (k q1 q2) / r2 Where F = Force K = Constant Q= charges R = distance between the charges This theory said that if there are 2 charges points then there will be force between them which is proportional to the product of the charges and inversely proportional to the square of the distance between the charges. This force is the repelling force or attraction force but it is not contact force. reference http://wildcat.phys.northwestern.edu/Lab/DOWNLOAD/electrostatics.pdf