Greetings everyone! I've been trying to find new ways of
introducing waves. I have a wave table, but the motor which vibrates the
wave makers doesn't always work all that well. Plus, it is sometimes
difficult to see some of the effects of wave interations. I think I've
found a new of showing waves on the overhead projector and its easy.
All I used were 2 transparencies that I had photocopied
concentric circles and 2 transparencies that I had copied parallel lines.
With the concentric circles, if you place them side to side, you can see
interference lines. If you take one of the concentric circles and
demonstrate what happens when it is reflected from a surface, I just fold
the transparency slowly over and you can see the reflection.
With the parallel lines to show reflection, again I just fold
over the transparency. If you slowly fold/roll the transparency it looks
like the waves are passing over one another. Or else, if you take the
two parrallel line transparencies, slide them over one another to see the
interference patterns.
I even placed a block on the overhead to give the effect of the
waves hitting the block and bouncing off. I think it really helped the
students to better see what was going on in the wave table and better
understand the diagrams in their texts.
I hope this helps some of you. Don't forget, I get royalty on
this idea. :^)