Open and Closed Pipe Length for Harmonics

[SUXinPHY]

Homework Statement

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?

Homework Equations

v=$$\lambda$$f

The Attempt at a Solution

sorry, i could not do it. i totally can't do it.

 

[Hootenanny]

Homework Statement

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?

Homework Equations

v=$$\lambda$$f

The Attempt at a Solution

sorry, i could not do it. i totally can't do it.

Can you start by telling me what a harmonic is?

 

[SUXinPHY]

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

the formula for fundamental harmonic is

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

 

[Hootenanny]

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

Correct.

the formula for fundamental harmonic is

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

That equation is only valid for tubes with open ends, what about tubes with closed ends?