# Speed of sound in tubes

1. Feb 4, 2009

### notpmaws

So my friend in a general physics class did an experiment testing the speed of sound by snapping their fingers and having it bounce through a tube open and another that is closed. They measured a faster speed in the open tube and I am at a loss why. Did they do the measurements wrong possibly or is there an explanation for faster speed of sound in an open tube? They measured the speed of sound in the open tube about 10 m/s faster.

I tried to do a search on the net but found nothing besides it changing the effective length of the wave and such, but not sure that effects the speed. Thanks.

2. Feb 4, 2009

### Staff: Mentor

How long of a tube and how was it measured? You'd need a measurement precision of 1/100th second to be able to measure a difference of 10 m/s.

3. Feb 4, 2009

### notpmaws

Hmm I am not sure how long of tubes were used, I think about 8ish feet. They just used a computer program and microphone and snapping their fingers to measure the sound wave bouncing back. Not sure what program they used.

Should there be a difference though in the 2 tubes or should they be the same? If different then why is that?

Last edited: Feb 4, 2009
4. Feb 4, 2009

### Staff: Mentor

There should be no difference. What is the precision of the timing device?