Coulomb’s Law Experiment EX-9930B

A conductive sphere is mounted on the end of an insulating counterbalanced rod and suspended from a very thin torsion wire. An identical sphere is mounted on a calibrated linear track and can be positioned at various distances from the first sphere. When the conductive spheres are charged, the force between them is proportional to the twist of the torsion wire that is required to bring the balance back to its equilibrium position. Introductory physics students can determine the Inverse Square Law in a simple experiment, while advanced students can perform investigations into all the variables involved in electrostatic repulsion.

Note:  This experiment can be performed as a standalone activity.  However, it can also incorporate data collection software for further analysis. The supplied files are for DataStudio software but they can also be opened using PASCO Capstone software.