1.) Quale punto sulla superficie della sfera ha massima velocita' istantanea?
2.) Se
3.) Quanto vale, al minimo, il coefficiente di attrito statico tra metallo e legno?
![Immagine](https://i.imgur.com/tWy7d2n.jpg)
Ah, I found it in 200MPPP P52. Another variant of this problem is in Russian olympiads too. And yet another same problem is in Kvant 1987 6th monthly issue. So yeah it is a super popular problem. The greatest speed will be of point Q. And this greatest speed is