Waves

Waves Wednesday set up includes tape measure, timer, and rope. 

This term I used push pins to mount the Monday RipStik run on the board. 

Rope wave calculations. I did only a brief handwaving demonstration using a golf ball that frequency and wavelength are inversely related: I feigned that the drop and bounce of the ball were akin to the wavelength. Higher drop and bounce, longer wavelength, lower frequency. Lower drop and bounce, shorter wavelength, higher frequency.

The SMARTboard at class start set up with the sound section.

I used a tidal chart to demonstrate that the tide was a wave with a long period, low frequency.  I also pointed out the wave form of the interference pattern that can be just made out above - the beat frequency between the moon and sun that generates neap and spring tides. 

Then I moved into sound. Once I remembered how to get the tone generator to work I discovered that the on screen oscilloscope would display the sound - the tone generator would continue to run even when not in the foreground. 

I tried to get the Virtual Oscilloscope up and running, but the site did not pop a microphone permission request and wasn't picking up the microphone. I did get a microphone permission request from the Musiscope, and a subsequent reload of Virtual Oscilloscope somehow granted that app microphone access. The Dood.al XXY Oscilloscope would not run on the modified Android version installed on the SMARTboard. 

Then I tried to generate tones with the ScienceMusic Signal Generator but I had forgotten how it worked. I also suspect that loading the code took longer than expected. I forgot that one clicks in the gray area to the left to get a signal. I was pleasantly surprised that the signal generator not only worked better than I remembered, but the Virtual Oscilloscope would display the wave form even with the Signal Generator tab now in the background. The SMARTboard browser usually shuts down background tabs.