I was trying to understand the Doppler effect across different mediums on the SE site and came across the question Doppler Effect and change in medium.
Though it's a homework question, I was attempting to understand the solution posted by the OP. Even after rereading and attempting it myself, I am unable to understand the answer posted. I believe the OP is now inactive based on his profile, hence I didn't post my query as a comment. I avoid asking it as a new question as it may be flagged as a duplicate. How can I get the said answer further clarified?