hi, i had an almost identical sounding physics depth study last term. i'll tell you what mine was like and what i did for it.
so how depth studies in my school's sciences work is that we document our entire process in a log book (a loose structure sounds like: light research, deciding on what experiment and how you are going to do it, aim, hypothesis, risk assessment, finalised method and equiptment, actual experimental data and observations, results tables and graphs, discussion and conclusion). and then using our logbook we had a 45 minute validation exam with some questions on our results and the rest on concepts relating to the concept behind our depth study.
ours last term were on ideal and real life systems and how conservation of momentum and energy apply to them (this is mod 1/2 content). we went to luna park and took a video of the motion of one of the rides (we all did the hair raiser bc it was linear motion and its easy to analyse) and put it through a software which tracked the motion and gave us our data - this was our real-life model. then we made another set of data using the formulas (ideal model). then we analysed it all.
honestly speaking to maximise your marks in your depth study the best advice i could give you is please please please don't procrastinate in it (aka. leave it to the last 2 weeks) bc you will def miss the depth of research/analysis/understanding you need for it if you rush it. and if you are completely lost, which i was, you need to ask questions as you go along and make sure you understand everything that is going on. if you are working in groups you should try your hardest to be doing smth useful or observing details as best you can so you can mention any discrepancies/nuances in the method in your discussion. and finally ask your teacher as many questions as possible and ask nicely for feedback (some teachers might refuse to look through your logbook/work bc its a depth study but you can always ask for verbal feedback e.g. "i did xyz, is that smth you would recommend" or " what do you think is the best way to do xyz" just try to finesse them if they don't give you feedback basically). religiously refer to the marking criteria and go over and beyond to the best of your abilities bc its a DEPTH study.
feel free to ask any questions