Can anyone help me find a proper illustration of a standing wave that comes as a result of the superposition of the travelling waves in a wine glass? I am looking for something like
(from this video at around 0:45) but I have additional questions.
Is the standing wave in the glass (filled with water to some portion) going through the water as well? Or just the air? Doesn't superposition go through only 1 medium, and that they must be the same for both waves to be able to superpose them? If I must draw my own, how do I know where it is and which direction it is facing?