Well I'm reading this book called The Physics of Superheroes (and I really like it).

First" />http://www.booksonboard.com/book_covers/300/108459.jpg
First I would like to recommend it to everyone on the vine. It discusses every physical aspect of superheroes (other then the miracle aspect of there powers) such as can Flash run on water or walls (sorry no).
Witch brings me to this I would like to conduct my own experiments to see up to what point each superhero's ability's be extended. For example up to what point can Superman take a punch (Methos said that Goku can kill Superman and I want to see if he is right). My guess is that here is my beast beat of finding out.

So up to what point can Superman take a punch?