I found the simple harmonic motion in this book pretty easy but some of the other topics such as projectile motion a little tricky. (btw I go to same school as you; Fort Street yeh?) but I'm in yr 11 as an accelerant for 3u maths.
HSC
2U Maths - 98% [5/98] (4 people tied at 99%!)
3U Maths - 93% [7/121]
Prelim
Chemistry - 98% [2/110] (Many people tied at 98%, one on 100%)
Physics - 84% [25/80] (Should have tried harder!)
Economics - 93% [8/80]
EngAdv - 80% - [40/160]
Stuff that I really dc about
SLR (1U) - Some fail mark...
Instead of Maths 2U, since you don't seem to enjoy maths, why not choose Modern History or Chemistry? Both are solid choices with high scaling, and seem to follow in the lines of the other subjects you have chosen (Bio & Ancient)