That's a good question, a bit late for me because I already did but well-timed for students choosing their IB subjects. It's not about what you know but about the way you think - some of my best students had very little knowledge of physics before they started the course but ended up scoring a 7. Conversely, some students who have studied physics for years do quite badly.

IB physics is not like all physics courses. It's no use practising loads of problems hoping that similar ones will come up on the exam (except maybe in the astrophysics option). IB examiners like to set questions where you have to apply what you know to novel situations and that means you have to understand the concepts not just remember the definitions. To help students decide I have made a little test. It's not based on years of research, just years of experience but hopefully it gives some idea as to the mathematical requirements and the way we think.

Link to quiz