AQA GCSE Physics Required Practical 9 Revision - reflection and refraction

Thank you for the feedback. The principle when graphing results from experiements is that the independent variable goes on the x-axis (and, by convention, the independent variable always goes on the left-hand side of a results table) (https://www.bbc.co.uk/bitesize/topics/zsg6m39/articles/zhmbvwx). I would suggest that not doing so contributes to confusion for all students, as providing and sticking to a consistent rule is helpful. If testing a relationship like F = ma, you will need to rearrange the equation to get it into the form of y = mx + c if you want to stick with this usual principle when graphing and obtaining a directly proportional relationship for the purpose of determining a gradient and hence proportionality constant. You're free not to not do this (which can be appropriate for some teaching situations, eg obtaining SHC from a graph), but I would recommend sticking to the principle of x-axis for the independent variable, as this is what the exam boards want and how it is examined (for instance, on this summer's AQA paper 1). In rates-of-change investigations, time is usually the independent variable, so goes on the x-axis. Hooke's law is slightly special, as techincally the 'F' in F=kx is a restoring force, so you are investigating how the restoring force varies with extension, ie, the extension is the independent variable. However, this usually only gets taught this way at A-level.