Quiz

Well, since nothing planned for the vacation actually worked out, with Ment's permission, I’ll at least pose a riddle. I myself solved it a very, very long time ago… Now I don’t even remember either the answer or how I solved it, but back then that guy said that I had solved it correctly, although his solution was much shorter and easier than mine. So here is the riddle, and I will try to find, recall, or re-solve it again. I’m not sure if I can solve it again, but here is the riddle. A hollow hemisphere of mass m lies on a table. Water begins to be poured into it from above through a small hole. To what height H will it fill up?