Day+18+-+Investigations


 * Day 18 - Investigations & special topics for GCSE**

We're going to look at GCSE investigation in this session. The plan for the day is to carry out some existing physics investigations from the various specifications. We'll break them down in terms of the skills, knowledge and learning that should be a part of them and look at how they can be best delivered. What we'll need is a list of suggested investigations. We'll get the most from the day by looking at the extremes - taking best practice from the good ones and redesigning the bad ones to make them usable. So firstly, please suggest candidates in advance and I'll make sure that they're resourced on the day.

Investigations: We'll be looking at resistance of a wire in a variety of ways, including conductive putty from SEP and the home made version from 'Squishy Circuits'.

Lens investigation Thermistor investigation LDR as X-Ray investigation

These are all topics that can motivate and inspire but require good teaching and careful linking of physics concept to earlier topics. These are exactly the sorts of area that need to be taught by physics specialists or they can be confusing.
 * Special topics:**

For teaching about optical instruments like the microscope and astronomical telescope, there's no sustitute for an old-fashioned optics practical. Get the lenses out and have at it. Students will get a great deal of satisfaction at making a working telescope with an optics bench. If you have the physical/geographical setup, leave a message that can only be read by telescope from the lab window on a wall or tree or in the window of a car. That learning is worth backing up, however, with simulations - some free material available here from Wolfram and plenty of other good optics sims around.

Amplitude modulation is well-illustrated with a demonstration. Instructions for building your own laser modulator are available here on the brilliant Scitoys website and there's a worksheet here with some parts linked to the Maplin website so you can build your own - hold ctrl and click on the labels and you'll go to the relevant Maplin product. You could build a simple am transmitter at the same time and demonstrate that the two devices do the same thing - the only differences being that they use different carrier wavelengths and that the laser is by its nature, very directional. You can use the laser modulator to show the advantage of FM over AM signals - connect it to a radio with talk radio or a speech presentation on MP3 (I'd recommend Stephen Fry's podcasts to anyone...) and then use polarising filters or some other way of reducing the beam intensity. There will come a point where a signal is audible but speech is impossible to recognise. At that point, interrupt the beam. 'On' and 'off' will still be learly distinguishable. Hence a signal too weak or interfered with to transmit speech (an analogue signal) will still transmit 'ons' and 'offs' (effectively a digital signal) without error. A second activity to illustrate this point is to play chinese whispers with a sentence and a number. Allow the pupils to write the sentence/number down as they hear it and make them get up to deliver it to a random person in the room. You can make this process model the situation more closely by choosing a nonesense word and transcribing it into alphabetic numbers - compare the analogue and digital transmissions. Students will notice that the 'digital' signal takes longer to transmit and receive - emphasis that it is only increases in processing speed and capacity that have enable d the digital revolution.

Teaching medical physics can be tricky for the non-specialist. If only there were some easy-to-remember website to help, like www.teachingmedicalphysics.org.uk (Now relocated here!). You should know roughly what the differences are between regular x-rays, CT scans, PET scans and MRI and understand the differences between each. Good guide here from Leeds University More detailed information can be found for example, this site has a good page on PET scanning and this page has a terrible joke about cat scans. There is a good guide for CT scanning on Imaginis and some more patient-oriented information on eHow. How Stuff Works is usually quite a good starting place for this kind of information, and doesn't disappoint with a comprehensive article on MRI scanning. If you want a more physics version, this article from Science Learning is quite interesting.