I am doing a investigation into the Wilberforce Pendulum and in order to find the position and rotation at any time I have attached my phone onto the pendulum in order to use Phyphox, a app that finds the acceleration and angular velocity. However, when I put the data into excel and use forward Euler to find the velocity from the acceleration, and the position from the velocity. However, this doesn't really work, and the velocity seems to drift downwards a bit, and then the position seems to drift down much, much more. I also took a video of the pendulum, and I compared this to the results to show that it isn't experimental error.
Do any of you know how to get the position data from acceleration, without this error?