Measuring the speed of sound with a resonance tube - physics demonstration / experiment

This is a demonstration of how to calculate the speed of sound in air, using a resonance tube filled with water and a tuning fork of known frequency. It was created as part of my university assessment - hopefully it might help someone in some small way!

Category:

Education

Tags:

• science
• physics
• demonstration
• experiment
• resonance
• tuning fork
• speed of sound

[azmcgazable]

@Test718 - both harmonics sound the same, the first will be the shortest, the third will be around 3x the length of the first. To help find them, you can calculate theoretical values:

If you have an 'A' tuning fork (f=440Hz), with the speed of sound ~340m/s, the wavelength can be calculated as 0.77m. Since the first harmonic is 1/4 of the wavelength, you'd expect the tuning fork to resonate when the tube is 1/4 x 0.77m = 19cm (give or take). For the 3rd harmonic, it would be 3/4 x 0.77m = 58cm.

[Test718]

How do you know weather you are hearing the first of 3rd harmonic. I'm guessing you start at the smallest length and then exend the tube out of the water futher until you hear another loud pitch.

[azmcgazable]

@prache5610 - yeah, the music and credits are very random. I mentioned it was for a university assessment, but the subject was actually about computer proficiency and using ICT for education. So the assessment was based on basic software skills, as opposed to the actual physics content. I just thought I'd keep it online in case it helps a few people with their physics homework...

[prache5610]

Physics + Rap = wtf?

Good work though