stationary waves

**FizixFreak** · Mar3-10, 06:24 AM

hi there i just wanted to know that how are waves reflected in an open air column and what do we mean about odd harmonics? thank you

**tiny-tim** · Mar3-10, 09:29 AM

Hi FizixFreak! Welcome to PF!

Originally Posted by FizixFreak

hi there i just wanted to know that how are waves reflected in an open air column

See the PF Library on open end

**FizixFreak** · Mar6-10, 08:22 PM

THE website great man thank you very much

**FizixFreak** · Mar6-10, 08:31 PM

but what about odd harmonics

**jtbell** · Mar6-10, 08:45 PM

Odd harmonics are odd-integer multiples of the fundamental frequency:

,

,

,

,etc.

**FizixFreak** · Mar7-10, 04:43 AM

i know that but why only odd harmonics are produced in an closed end column?????

**FizixFreak** · Mar9-10, 11:07 AM

Originally Posted by FizixFreak

i know that but why only odd harmonics are produced in an closed end column?????

Originally Posted by jtbell

Odd harmonics are odd-integer multiples of the fundamental frequency: , , , ,etc.

no replies

i hope i m not wasting your time but i really need to know this stuff

**Stonebridge** · Mar9-10, 12:16 PM

Originally Posted by FizixFreak

i know that but why only odd harmonics are produced in an closed end column?????

Because the closed end must be a node and the open end an antinode. This means that only 1/4 or 3/4 or 5/4 or 7/4 etc of a wave can fit in the tube. This gives only odd harmonics.

**jtbell** · Mar9-10, 12:19 PM

See the following page:

http://cnx.org/content/m12589/latest/

Scroll down to the diagram labeled "Allowed Wavelengths in a Stopped Tube."

How do the second, third and fourth waves compare in wavelength to the first one? (How much longer are they?)

Notice that in the first one (the fundamental), you're seeing only 1/4 of a wavelength.