This is a very well known physics problem and i already know how to solve it. How close to the edge of a 24kg table can a 66kg person sit without tipping it over? I think everybody can see the table and what's happening in there. MY QUESTION IS: Why don't we use the normal reaction due to the farther suportting?? I mean, when we calculate total torque about one supporting, we still have the other support in which there's a reaction force ating. And i think this force is as legitimate as the gravity forces of the table and person... I would be really glad with any answer trying to explain why is this approximation made or if I'm completely wrong in my reasoning! Take care!