Whilst the preliminary physics and chemistry course are not directly assessed in the HSC examination, all prelim phys and chem content is "assumed knowledge" for the HSC course.
Eg, using the wave equation in world communicates is also applied in HSC course topic 3 - ideas to implementation, but you won't be taught it over again, just be assumed to be able to use it.
also, you are assumed to be able to do all the chemical equations learnt in prelim