One of the things I find hardest, but most satisfying, about unstructured education, is the question that appears at short notice, related to something that C is doing. Then I'm struggling with the 'where do I start?' problem, trying to explain something that is now second nature to me because I've known it so long. Trying to remember back to how I was introduced to the subject is almost impossible, not least because I probably read the text book and learned it that way. C is still a bit young to take to that sort of thing though, so we improvise and try to lay the groundwork for when he's ready to come back and tackle the subject some more.
Over the weekend the HotWheels track came out of wherever it had been stored. This is the one that hooks over the top of a door, with a track that drops down steeply and then angles up so the car flies off the end of the track and hopefully through a hoop some distance away. From this we got to some physics equations, namely v=u+at, s=ut+0.5at^2 and v^2=u^2+2as [*] As a bonus, I managed to link in C's experience of playing the lunar lander game at the National Space Centre as another example of using the equations. In the absence of graph paper (must find some) to add in a lesson in how to plot graphs, I fired up OpenOffice and set up some equations and a graph on the spreadsheet. This gave a nice demonstration of things such as having the launch trajectory at 60 degrees landed in the same place as having it at 30 degrees, and the fact that 45 degrees gave maximum range. We also covered the time taken for the 30/60 trajectories and discussed which one would be easiest to get through a vertical hoop.
I may put together a gadget with a couple of light beams and a timer so that he can set the beams at different heights and record the time taken between the beams for each height. He loves gadgets, and I'm sure that making a few would encourage the learning process somewhat. At some point I might even let him assist in building, if I think he's OK using a soldering iron. One learns very quickly which end to hold and picks up useful tips such as not trying to catch it if it gets knocked off the bench and to pay attention when using it.
[*] no doubt known to those who did physics O-level. The modern GCSE equivalent is probably to write an essay on the evils of speed when it comes to motor vehicles.