No I got a 9 at GCSE and I’m working for an A, not gonna get an A*, as I’m not good at physics and a lot of the applied is physics mechanics so that will be good for you. A 9 at GCSE is more like A (some people A* but rare). A few people in my class who got a 6/7 are getting between a D-U but if you put in a lot of effort, and you do physics which is very good for a level maths, you could get a C. Idk you personally, so maybe a B. It depends on what you need. It’s very interesting, and probably worth it for you.