A more convenient method to predict gravitational acceleration (g) using smartphone’s proximity sensor in a simple pendulum experiment

Abstract

The application of smartphones in physics learning is inevitable because of the advanced technology installed in them. The simple pendulum is a classical topic in physics relating to gravitational acceleration. Smartphones are equipped with a proximity sensor that can record the period of an oscillating pendulum. A method to determine gravitational acceleration (g) using a smartphone proximity sensor in a simple pendulum experiment was presented in this study. This proposed method is more convenient and straightforward because it does not require additional equipment apart from string and bob. Furthermore, the simplicity of this method is assisted by software used that is able to display directly the results of period measurement that subsequently were applied to calculate the gravitational acceleration (g). The string length was varied to analyze the consistency of measurement results. The calculated g values were compared to the local gravity value and produced a relative error with a range of 0.11%–0.54%. The reported g value combined with uncertainty propagation was 9.75 ± 0.02 ms−2.