You will need a tall container (such as your plastic bottle), an 8 – 10 inch long 3/4 inch diameter straight pipe (or similarly shaped cylinder – even a thick soda straw works but not too well), a ruler, and a marker. Fill the container with water, and insert the pipe so that only about 2 inches of it will stick out on top of the water. What you have just built is an adjustable pan-flute. Try it out and practice until you find the right angle to make a clear sound when blowing in a slight angle over the top opening of the pipe. Once you honed your technique, start moving the pipe in and out of the water and listen to how the sound changes. Practice some more to get proficient in producing and adjusting desired sounds.
Starting to sound like you should perform for money? Great. It’s time to tune our instrument in a more scientific way. Let’s first set up our lab equipment. If you have a smartphone, perfect. Given all the available tools these days, we will have an easy time. However, if you don’t have a smartphone, don’t worry – we will play it by ear… (just skip the next couple of steps)
On your smartphone open your applicable application store (e.g., Google Play or Apple App Store) and search for a free instrument tuner that has also the ability to indicate exact frequencies. For a well-working example, see: Tuner – DaTuner Lite! (Links to an external site.) https://play.google.com/store/apps/details?id=com.bork.dsp.datuna
(Besides the big note indicator, notice the exact frequency readout on the bottom left.)
By the way, while you are there, notice that there are a lot of free helpful apps for pretty much any scientific application, (e.g., Gauss Meter (Links to an external site.) https://play.google.com/store/apps/details?id=com.keuwl.gaussmeter ), and you can certainly also use a complete spectrum analyzer (e.g., Sound Analyzer (Links to an external site.) https://play.google.com/store/apps/details?id=processing.test.soundanalyzer ) instead of an instrument tuner; however, as with any lab equipment, make sure to familiarize yourself with its function.
If you don’t have a smartphone, use an online tone generator (Links to an external site.) https://www.szynalski.com/tone-generator/ on your computer. Set it to the desired frequency and play the tone. Then play and adjust your makeshift pan-flute to match the sound (with an 8-10 inch pipe, you should be able to play from about 440Hz, the Violin A note, with the pipe barely in the water, to about 2000Hz with only about an inch of pipe left out of the water). Select a handful of frequencies (at least 5) within that range for sampling during your experiment.
For the experimental phase, document the length of pipe that is out of the water and the matching frequency of the tone that is produced by that length (a table setup is again a good idea). Take at least 6 measurements at different pipe lengths (5 if using tone matching). As a technique in your methodology, consider using the ruler and pen to mark the different intended test lengths on the pipe before starting the experiment. Then just match line and water level, hold it in that place and make your sound measurement.
Once you took your data, complete your protocol, to include a diagram and evaluation of pipe length to frequency relationship. For the theoretical framework in your protocol discussion, consider what you have learned about standing waves in air columns. The overall scientific question in this experiment is whether it is possible to numerically predict a required flute length based on desired frequency/wavelength. Therefore, your conclusion should address that relationship.
we already introduced protocol documentation for our experiments. In this activity, we will add some graphical depiction of results to it. For the following experiments, prepare an experimental protocol, similar to what you learned in Module 3. (see Protocol Template (DOCX))
Additionally, you will need to prepare a table and a corresponding diagram (see example below). MS Excel or similar tabulation and graphing tools can be utilized and should be explored for this task.
Read the following experiment activity description, and prepare the first half of your protocol, detailing the scientific problem, the theoretical background, your methodology, and your predictions for the experimental results. Then conduct your experiment in accordance with the activity description.