Object Tracking for frequency

I am trying to find frequency of ocsillation of a spring by its video of oscillation, but i am unable to plot its oscialltion(y-coordinate) of the selected tracker,I am reading the first frame of the video and selecting a region in it, but once the region is selected from first frame, I am unable to track its trajectory in the whole video and eventually plot it versus time.

Task Completed by me- 1. Initialising a position on the video which I want to track

Unable to figure out how to track the trajectory of the selected position

Please try to help me with this.

PFA the video which i am using.

[Gabriel Delgado]

Did you have sucess in this task? I'm trying to do sothing like this, but in my case it's an object that oscilate in 2 dimensions. Could you share your code?