My last entry gave a couple of tips for exams in general. Now, here’s a tip specifically for the NZQA scholarship physics exam. In part, it comes from an assessment of the interviews I’ve been doing with first year students and practising physicists on the way that mathematics is used in physics.
One really strong theme that practising physicists emphasize, is the conceptual nature of physics. One of my interviewees, who works in a successful NZ science-driven industry said this:
The ability to discern the important from the less important is a paramount skill.
In other words, doing physics well is down to identifying what are the bits of physics that matter, and not getting carried away with the bits that don’t. When faced with a problem, the very first thing he needs to do is to get down to the basic, core science principles of what’s happening. He doesn’t start writing down equations, or doing calculations, or deriving formulae, until he’s sure what concepts are going to matter for his particular problem.
It’s also clear that my first year students don’t identify with this skill so strongly. There are hints in the interviews that some of them do, a bit, but it is not anywhere near as strong as for the practising physicists. It’s a difficult skill. And it’s one that often isn’t really taught – either at school or university. (I would suggest we try to change this – I would say it’s more important than knowing the technical content of the subject.)
Having looked at the scholarship physics questions for several years, I know that they are written to identify those students who grasp physics over those who can simply rearrange equations and plug numbers into them. Being able to do algebra alone isn’t going to get you scholarship (though not being able to do simple algebra will seriously harm your chances). What is going to help, above all else, is to be able to identify what parts of the subject are relevant to particular situations. This takes practice.
So, my tip is this: The first thing you should ask yourself is "What is this question about?" – i.e. what areas of physics is it going to draw from? (Read the title of the question – it can give you some hints) Then, ask "What concepts am I going to need to draw together to tackle this?" And "How do these concepts fit together?" Then, and only then, should you think about writing down equations. Otherwise, you’ll get lost in a sea of irrelevant algebra.