- #1
Spookie71
- 16
- 0
Homework Statement
The question I'm working on is
What is the third longest wavelength that resonates within an air column 33cm in length, open at one end and closed at the other.
First the diagram:http://http://i215.photobucket.com/albums/cc10/Spookie71/image0-12.jpgI actually have the answer to this one as it is a sample question in the textbook however I'm not clear on 3 resonances and the diagrams drawn for them and the eventual equation to solve.
Why is this considered 3 resonances, I believe I see the first two with each completed with a node. Then there is the start of another which goes for about a 1/4 of a wavelength and ends up as an antinode at the end of the column.
There is the matter of the equation I use to solve the equation:
l = [tex]\frac{(2n - 1)\lambda}{4}[/tex]
The n = the number of resonances but what does the -1 / 4 stand for, the 1/4 wavelength extending from the node to the antinode at the end of the column?
Can you please explain for me?
Scott