Greetings, PF. With many recommendations and just enough confidence in my ability to solve problems, I've recently purchased the renowned Problems in General Physics by I. E. Irodov. With excitement, I opened the book and read the first problem. It took a lot of thinking to solve the first few questions, and they all were challenging on their very own ways (which, I think, is what makes this book so infamous). However, I was able to encounter problems in which I just couldn't model the situation mathematically within my abilities. Of what mathematical background are you expected to have in order to solve these problems? And are the problems to become gradually harder? If so, that isn't good news, because I am struggling hard right now. As always, thanks in advance.