Doing sound waves: get an airzooka Interesting approach to sound levels for Y8: Use a datalogger to record sound intensity produced by ear phones by holding the ear piece directly on the sensor. Many students will have an mp3 player or cd player (some may even have a walkman) unless your school has banned them. Ask them to set the volume to their normal listening level. One of my students this morning registered 100dbA as the ambient level with peaks up to 115dbA. This was in a 10s sample. Damping sound. If you can raid the music dept:
waves - wavelength of microwaves...marshmallows on plastic tray put in microwave oven..remove the rotating glass plate first med power for about 1 min (may have to experiment depending on microwave) marshmallows melt at approx wavelength as standing waves set up in microwave oven. I remembered one bizarre experiment the other week. Maybe possible to do in class, but memorable anyway: Measuring the speed of light with a microwave over and a plate of cheese. It works!
New (to me) product to use when teaching about colour addition - an LED bulb (fits standard socket) that contains red, green and blue LED's - using these it cycles through the colours red,blue, green, yellow, cyan, magenta & white (taking about 3 seconds on each colour.