Open and closed pipe (Help)

1. Jul 31, 2008

SUXinPHY

1. The problem statement, all variables and given/known data

a pipe in air at 20 degrees celsius ia to be designed to produce two succesive harmonics at 240Hz & 280Hz. how long must the pipe be, and is it open or closed?

2. Relevant equations

v=$$\lambda$$f

3. The attempt at a solution

sorry, i could not do it. i totally cant do it.

2. Aug 1, 2008

Hootenanny

Staff Emeritus
Can you start by telling me what a harmonic is?

3. Aug 2, 2008

SUXinPHY

harmonics are frequencies of a wave which consits the fundemental frequency.

the formula for fundemental harmonic is

fn
= v$$/$$$$\lambda$$n
= n (v$$/$$2L)
= nf0

4. Aug 2, 2008

Hootenanny

Staff Emeritus
Correct.
That equation is only valid for tubes with open ends, what about tubes with closed ends?

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