Using a Simple Pendulum to Calculate the Distance Between Two Train Stations

In this article, we demonstrate the use of a simple pendulum to explore the concepts of kinematics and dynamics. A simple homemade pendulum and a phone-based accelerometer are used to determine, at various points in time, the acceleration of a moving train. The dynamical and kinematics data from the homemade pendulum and the accelerator can then be compared, and this in turn highlights the relationship between dynamical and kinematics quantities. This project is originally part of a coursework requirement assigned to the first four authors for their introductory classical mechanics course at a university in the summer of 2020. Similar ideas have been explored earlier independent of this work, but this work will focus on the detailed description of our approach and using updated technologies as our benchmark. The project is one that can be implemented readily as an activity in high school physics classes.