Newtons coulomb's low demonstration

Study the concepts of Newton?s and Coulomb?s laws with this apparatus.This apparatus can be used to demonstrate repulsion, attraction of charged bodies and provides the ability to measure the angle between the 2 strings and thus the force between the two charged spheres. The charge can be provided by a Wimshurst machine or a Van de Graff generator or by simply rubbing a plastic rule with on a duster. Includes manual.