Looks like not much. The book is about using Python to implement numerical methods, mainly about teaching the Python part, and that's all explained. You might be missing motivation if you don't know any physics, but even so, basic mechanics using differential equations seems to be enough to give context, at least for the earlier parts
Just to give a bit of flavor, I was a math + physics major in the 80s. The physics curriculum had some oddly named courses such as "theoretical physics" that were not really physics courses but were meant to give you the math and computational background needed for the more advanced courses or for graduate work. The math was stuff that wasn't covered extensively enough in the math major courses, such as vector calculus.
