If you missed today:
1. We collected Great America money.
2. We studied wave reflections from rigid and non rigid boundaries by working with the PHET Simulation Waves on a String (important that you experience that a wave reflects inverted from a rigid boundary but erect from a non-rigid boundary, also to observe that a wave has the same speed in a given medium, and as a wave passes from one median to another its frequency does not change so its wavelength thus its speed must, etc.)
3. We observed all the above wave phenomena in addition to dampening to remove energy by making the wave work and getting more wave energy to transfer into a new medium by adding a transformer that starts out as the same medium and slowly changes its shape to the shape of the new medium by using the WAVE MACHINE.
4. We watched the slinky VHS video about how slinkies got their start again and then let students go out in the hall and try to get them to walk down the steps.