Quantitative estimates of the electric charge for a classical electrostatics experiment

Abstract

Despite the widespread use of the charged tape method to demonstrate electrostatic interaction and the advances in affordable sensors that can directly measure electric charges, there is no detailed analysis of a quantitative model for such experiments. As a result, we present two different theoretical approaches that allowed us to quantitatively estimate the amount of electric charge present on transparent tape. Our first model assumed that the entire electric charge was concentrated at the center of mass of the tape and gave a simple algebraic solution, which came close to the order of magnitude of the actual electric charge measured with a PASCO charge sensor. Our second model approximated the sticky tape as a linear uniformly charged object. The estimated electric charge based on the uniform charge density model is closer to the measured value of electric charge than the value found by approximating each piece of tape as a point charge. Based on the statistical test, the experiments did not support the predictions of the point charge model. At the same time, the statistical test validated the uniform charge density model with a p-value of 0.01.