RipStik waves and the speed of sound

In preparing the RipStik run four sheets of poster pad were inadvertently detached from the pad. This led to a four sheet run. 
Gusting breezes were again problematic. With the plan to return the run track to A101, taping down was ruled out. Books were used to hold down the poster pads sheets. This meant ensuring the board remained on the centerline to avoid colliding with a book.

The books are old textbooks no longer in use.Spring term attempted to use the classroom, but the track was almost invisible and staying straight down the centerline was hindered by the lack of sufficient lead in distance.

The RipStik run on the board.


The run was timed at 2.697 seconds. The white board allowed completing the wave on both ends, which led to the use of three seconds for six waves. The wavelength was calculated off of a single wave, not all six, and came in at 0.65 meters. The amplitude was 0.06 meters.

All six waves were used to calculate the period and frequency. The run was deliberately moderate in velocity, an attempt to use a lower velocity than in the past. This made centerline maintenance more problematic. A summer head cold also impacted balance and stabilizer.

The period was 0.5 seconds and the frequency was 2 Hertz.

The velocity of the wave along with the equation for the wave.

An Erlenmeyer flask was used to try to show resonant frequencies. Maybe a graduated cylinder might work better?

Clayton and Emars work in finding the resonance point.

Mary-ellen and Ruthie adding water as they search for resonance

Erick and Jonald record a resonance distance

Eray pours water back into a beaker

Looking for resonance 

Board notes


Aggregated results in Desmos. This version of laboratory ten works well and produces a previously unseen mathematical model. The downside is perhaps that mathematics obscures how the speed of sounds "falls out" of the equation. Too, the issue of what is happening in the tube is certainly unclear to the students. 

Note that in the above chart a 206 cm, 159 Hertz data point was obtained using an empty graduated cylinder, the Smartboard speaker, and an online tone generating app. This term also included the newly added 1024 Hertz tuning fork, although that data point is not on the graph above.







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