physics overall i found is a really theory based subject so as rahul and others have mentioned the maths and application involved isn't extensive
physics space: very interesting and theory fileld core, i found myself this core had the most to remeber and for me was the most challenging becuase of the amount of information that had to be absorbed
physics motors & generators: simple and straight forward, doesn't hav any difficult concepts to take in, shouldn't be too hard to tackle
physics from ideas to implementation: favourite core for me, simple to understand and grasp and not too demanding, some issues might be hard to grasp at first but they are easyto get ur head around
option medical physics: very very simple, to demonstrate, here is my experience.. i was originally doing geophysics and after realising there was absolutely no info on it watsoever (hopefully this yr they bring out some publications for it) about 4 days b4 myphysics hsc exam i changed to medical physics... i got it all done in 5 hours and frankly i think i blitzed it in hsc.. all in all this option is very interesting and easy, not much maths is invovled at all but some concepts especially PET might catch you off gaurd..otherwise its very interesting and i highly recommend it
chemistry was probably my most challenging of all my subs not to say it was difficult, just alot of content to remember
chemistry production of materials: pretty interesting and more so an extension on wat u hav learned in prelim on carbon chemistry, it also contains info on electrochemistry and nuclear chemistry, found this core rather itneresting
chemisty acidic environment: great core as far as i am concerned my favourite out of the three, really easy concepts and not too challenging
chemistry monitoring and management: lots of content to remember but nothing to difficult, really interesting core all in all
option: shipwrecks and salvage: excellent option and very easy, mostly deals with electrochemistry. found this option very interesting and learnt alot from it..highly recommended IMO
anyways good luck all ur science buffs..dont forget biology either...excellent subject lol
catch yas later
telepathetic