Category Archives: Resources

Testing the Wave Equation in a Gratnells Tray

Ripple tank experiments are not really class practicals, they are usually demos, but we do a block of work on Waves in Y8 and again in Y10 and so I wanted some practical work to go with it. The fact that the GCSE has a required waves practical that is really only a demo added impetus to my thinking.

I started with the classic AQA A level ISA experiment (PHY-3T-Q09) where multiple crossings of a gratnells tray are timed and the waves’ speed is calculated, and tried to build something from there.

By adding clockwork dippers made from chattering teeth toys to make a wave train, we got a set of practicals that work quite well. However, the match between the measured wave speed and calculated wave speed from the wave equation is far from perfect. I think there are probably two reasons; the dipper frequency varies quite a lot (we could extend things by getting students to measure their own dipper frequency instead of demoing the measurement of one, as has been our practice so far), and I have a suspicion that the single waves do actually run a bit faster than the wave trains made by the dipper.

The worksheets (follow the link below) are for four or five lessons and are deliberately tough. We leave higher groups pretty much to their own devices with them and give more help to lower groups. We’ve tried it with several groups now and think it has some value.

Waves Practicals

I’ve left in the notes for the two speed of sound experiments, which we only do, a bit later on in the course, if we have time.

If more of us take this up then I am hoping someone will have a good idea for making a more reliable dipper, or even get someone to manufacture one.

Introduction to Lower Sixth Physics Document

In 2017 we have been given more time in the lower sixth to teach Physics, we are now up to five hours a week. To take advantage of this I have written a “Mathematical Methods Introduction”. It is meant to be a hard introduction to the kind of maths we do in Physics, but its content that is slightly tangental to the course; there was no point in repeating what we already do.


lower sixth maths methods intro

Notes for Y8 Energy

These are currently (August 2017) incomplete because I need to add in some HW exercises.

The Waves portion for Y8 is my next job.

Energy purists will notice that I haven’t adopted the energy newspeak. This because we use CIE for our GCSE; CIE have not yet indicated that they will go over to newspeak. I think (having looked at their sample exams) that someone who used this approach would be OK in taking the new AQA GCSE, which is deliberate because some of our boys change schools and because CIE might change eventually.

Y8 Physics Course Notes Energy

AS Physics – Particles

Both my old (Beithaupt) and my new textbook (England etc) for AQA AS Physics seem to like to do particles in the opposite order from tradition. The trouble with this is you are talking about photons before you’ve explained where the idea comes from. I’m afraid I’m traditional and like to teach it from a historical point of view. To that end I follow this timeline:

Particles Early Timeline

When I get towards the photoelectric effect I follow the history as laid out by Klassen:


I illustrate the history with an apparatus diagram from Von Lenard’s Nobel Lecture:


And the graph that Millikan produced when trying to disprove it, from his Nobel Lecture:


And although not strictly in the A level, having introduced De Broglie, I like to go through the Bohr atom as well:

Hydrogen and Bohr



Pendulums Project

This is a project that we give to Year Nine across six hour long lessons – which in our case takes six weeks. It was inspired by reading about the dutch method of teaching science as recorded in the TIMSS International Video study. The Dutch seem to set assignments that require the students to pace themselves through long term assignments, and as our school was having a push on independent learning I thought I’d dip a toe in the water.

The project is mostly about experimental design and utilises the fact that we have enough datalogging kit for classes to be able to measure the period of a pendulum in more ways than just hand timing.

We’ve been doing this project for at least four years now. The boys don’t like it much – especially the top sets, because we refuse to help them and they are used to being able to get our help in setting experiments up, but I, and I hope my department, think it is a useful exercise. It certainly means that we do not have to bother covering pendulums again until Y13!


They are always surprised when they get an increase in time with swing size (pendulums only do SHM for angles of roughly 6 degrees or less) – our fault for the way we introduce pendulums in Y7 I suspect. They often get a tend when changing the bob mass because they do not take into account the fact that the change moves the centre of mass. They do not know what to do when there is no trend – again our fault, we always set experiments that have trends. And they always conclude that the computer readings were better, when actually the resulting trend from that experiment is a curve and not a straight line because of the mass of rod and probably the inertia of the pulley. Even when they notice that it gives a curve, they still conclude that that was the better experiment!

I’m always thinking that I ought to do another, but although I do have a sixth form project along similar lines, I’ve never yet thought of a topic which inspired me to do another for KS3 or 4.


Writing Up a Practical

I suspect this will be the most contentious piece I’ll write, but I’ll hide it in “Resources” and it’ll never be found!

I have particular views about write-ups, and I tend to be pretty uncompromising about them, on the perhaps tenuous basis that many years ago I have had a couple of papers published on experimental Physics.

In KS3 and Ks4 the idea of an “investigation” is rather silly – the kids do not know enough about Physics, or even the kit that a department possesses, to design and test anything but the most trivial hypotheses with uninteresting experiments. Why then are we routinely expecting them to include “hypothesis” and “evaluation” in their lab reports – especially if it is an experiment we gave them instructions for in the first place? I know you can answer “because the ISAs require it”, but they’re gone now – and really?  Once again the hypotheses are so trivial there is just no need to have been reinforcing the process through the previous however many years. You are teaching them that science is trivial. As for “evaluations”, what can they evaluate? You are encouraging them to write “I enjoyed it and I think we did it well”. Who cares!!??

And so these are our write up instructions that must be followed throughout KS3 & 4 if they want a decent effort grade :


and the glossary:


For the level our boys work at, and certainly with a parent’s help, I regard the “Method” portion as pretty self explanatory, and so requiring these instructions to be followed frees up our marking effort of comments and advise for direction at what I regard as the hard bits – drawing and interpreting the graphs.

Just as an aside:

In a recent inspection of the department it was suggested that our exercise books were a confused mix of write ups, notes and problems. I’m trialing these lab books from Rhino for all write ups with a Y10 group to see whether this helps. So far it is going very well and I suspect that next year we will be rolling lab books out across more of the department.

KS3 Grading/Marking Policy

From what I read about marking in UK schools suspect that this is of very little use to anyone else, we aren’t ofsteded so I’ve no idea what they’d think.

Our school sends home regular updates with a level (yes we still do levels) and an effort grade from 1(good) to 5(so poor it is very rarely given). Parents are often less concerned by the level than by the effort grade, and so we have to be prepared to justify it to them and to the SLT. With this, and the idea that kids only read their grade and not the comments, in mind (boys don’t tend to be competitive about the amount of work they put in!), we stole an idea from our Maths Department, which has since spread to other departments. The idea is that homeworks should only be graded on their effort (ie 1 to 5) and that it should be the ticks and crosses and comments that convey how the Physics went. It is a lot easier to judge effort than level on single piece of work. Then a mean of the grades received since the last report home can be the easily justified effort grade on the next report home. It also means that boys in lower ability groups do not have to consistently get low grades. It has worked remarkably well, marking is much easier and when, as is quite often the case, our grades that are sent home are questioned as harsh we have our justifications ready.

Of course if you are going to go in this direction you have to make sure that you have documentation explaining your expectations in place, and so the following document is on our VLE, for the boys, but mostly for the parents:


Imaging in Year 9

In Year Nine we have put several bits and pieces from across the KS3 and KS4 syllabus together into a topic that we called “Imaging”.

Imaging contains the obvious stuff like Pinhole Cameras, Lenses, the Eye, and the EM Spectrum, but also some less obvious stuff like False Colour Imaging.  False Colour Imaging is included because we have done quite a lot of work with the Faulkes Telescope Project where we obtain individual black and white images that need combining to give an RGB picture (there are some examples of our work on this site).

As with our Year 7 programme, textbook support for this work is a bit sketchy so we wrote some notes to support it:

Year 9 Imaging

And a worksheet for a lesson on False Colour Imaging based on Adobe Photoshop:



Year Seven Physics Textbook

Because we teach Physics as a separate subject from Y7 it is tough to find appropriate textbooks at KS3.

In Y8 we use a mixture of Johnson’s “Physics for You” and Philpott and Clifford’s “Physics 11-14”.

In Y9 we use “Physics for You”.

We’ve toyed with the idea of using Reynolds’s “Complete Cambridge Secondary 1”, but at the moment I can’t justify the cost.

All of which leaves us without a textbook for Y7 so we wrote our own as a PDF that the boys are then required to access through our VLE. Feel free to have a look and tell me what you think. (I’m not sure that every single exercise is our original work, so if you happen know where one came from, do let me know so that I can credit it – or remove it if it’s yours and you want me to!)

Y7 Physics