Thank you Newton!
Now it works at least for as concern the floor, I have added a terrain that covers all the floor of the level , invisible flag, and I have given him the Newtonterrain function, and now the objekts don't sink in the floor, but there is an other problem, that is that of the walls,
the objects sinking in the walls. I have an other question for you, that is for the gravity, because it is too low, how it could be increased, for do it more realistic.
Greetings Salva