November 26, 2013
Welcome to my first episode of Stoked About Science!
I’ll be creating frequent episodes that involves cool demos, experiments, projects and challenges.
So, without further ado I give you:
Episode I: The Phantom Wineglass;)
Here are links to the free apps for detecting frequency that I mentioned in the video:
feedback detector for apple devices
audio spectrum monitor for android devices
And here is the video with the experiment and challenge:
Find some open space near a school where you can make a loud distinct sound (slapping two boards together or hitting a hammer against a chunk of metal or something like that). Stand as far away from the building as you can (at least 50 yards….100 yards is better) while still able to hear the echo of the sound you made. Have your partner (or you) start the timer as soon as the original sound is made and then stop the timer when you hear the echo. This is where being farther from the building makes it easier…then you have more of a delay between the original sound and teh echo. Repeat it four more times. Then you can use the middle time value as your average. Next you’ll need to figure out how far you were from the building. You can use a tape measure, or a rope or extension cord or count your steps to the wall if you don’t have any other method (then go home and measure how big your steps are). Don’t forget to double the distance because the sound travels to the building and then back again. The last step is to find the speed of the sound wave you heard by dividing the distance the sound traveled by the time it took
Speed = Distance/Time.
Make a wine glass sing (most thin-stemmed goblets will work—-get one at a thrift store or Walmart if you don’t have any). If you are really good then get several and play a little tune.
Report your results:
Let me know what you got for the speed of sound by make a comment below. I also want to see how many of you can make the wine glass sing! Email me some videos of that.
Have Fun and thanks for watching :)
PS: Students and Parents feel free to leave me a comment or shoot me an email with any feedback or suggestions on any part of this science experience.