Hello, Currently, I attend one of the most difficult HS in America (magnet school, ranks in top 10; won't specify for privacy) and I am currently taking AP Physics C without any prior physics knowledge. I have the hardest teacher among them all (apparently taught at MIT before). His problems for the test are really difficult and the problems we receive for homework/practice are textbook problems from Tipler and Halliday. I currently use the Tipler textbook to study prior to class (is this fine?) Where can I find more difficult problems that test you on Physics C knowledge, that go beyond the textbook problems, yet stay within the concepts of the AP (or the course in general)? The textbook problems are a joke compared to his tests. Also, I currently struggle in circular motion, which occasionally comes up with each concepts. I really have to understand them to heart, to know what to do in the problems my teacher gives. We finished kinematics and forces and we will be studying on work/energy tomorrow. Also, is there any other tips, or useful videos/guides out there? I can send you the test problems if that helps with the level difficulty (I will probably be getting back my forces test this week -- so let me know). Most of the questions in the forces test was circular motion, so I struggled. Thank you.