What referential should I use? Ping pong and water cup

Question

I'm trying to modelise the ping pong and water cup experiment. They were already questions on stackexchange about this:

Why does a ping pong ball bounce higher when it is dropped together with a cup of water?

but I would try an approach with Archimede Force and superficial tension.

I want to apply Newton's law on the ping pong ball, but the water and the cup are moving too and I don't know how it works in that case or how to modelise it... What do you think about it?

Answer 1

Since the experiment can replace the water by sand or by a poorly bouncing heavier ball I think the approach with Archimedes law does not work better than the explanations in the other link.