Huh? TBR Physics, Book 2, Pg. 18.

[pfaction]

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"At both openings of an open pipe there will be an antinode. All of the harmonic frequencies must also meet the restriction of having aninodes at the end of a pipe."

TPR says pressure nodes are at the open ends of the pipes, similar to a string. ?

 

[syoung]

EK has open pipes L = n(lamda)/2 where n = 1, 2, 3
both ends are antinodes.

 

[pfaction]

So then TPR is wrong? Any chance you can post a picture?

TPR:

TBR:

 

[syoung]

Sorry to bum you out, but your second picture says open pipes have antinodes. plus for EK its on page 106, no camera sorry.
a string tied down on both ends and a close pipe and an open pipe are all the same L = n(lamda)/2 where n = 1 2 3
but for a open and close pipe and a string with one end tied down it's L = n(lamda)/4 where n = 1 3 5

 

[pfaction]

Right...so am I reading it wrong? I read the top picture and the bottom two pictures again. They seem to be contradictory

 

[syoung]

No... please quote out the 2 parts you think are contradictory. I'm having trouble reading the giant ass un-resized picture >_<

 

[syoung]

Ok i just read what you saw. Which picture is from where?

 

[pfaction]

Top: TPR
Bottom 2: TBR.

 

[syoung]

TPR is wrong.
open pipes have 2 anti nodes. closed pipes have 2 nodes (like a string tied down on both ends)

http://www.physicsclassroom.com/Class/sound/U11l5c.cfm
open pipes

 

[syoung]

http://www.phys.unsw.edu.au/jw/flutes.v.clarinets.html#time

Ok this makes a little more sense. It explains why TPR said what it said.
There ARE pressure nodes at both ends of the open pipe, but each end has displacement ANTINODES, which is what we draw. In closed pipes, there are pressure nodes at both ends of the pipe and displacement nodes. In closed/open pipes, there is a pressure node/displacement antinode at the open end and a pressure node at the closed end.

 

[hellocubed]

closed pipes have 2 nodes (like a string tied down on both ends)

No, Closed pipes do not have 2 end nodes.

one side is an anti-node (open end) and the other side is a node (closed end)
http://images.tutorvista.com/content/waves/closed-pipe-vibration-modes.gif

 

[chiddler]

No, Closed pipes do not have 2 end nodes.

one side is an anti-node (open end) and the other side is a node (closed end)
http://images.tutorvista.com/content/waves/closed-pipe-vibration-modes.gif

i think just semantic difference. pretty sure he meant double close ended pipes.

 

[chaser0]

Huh...? Theres no such thing as double close ended pipes...

 

[syoung]

i think just semantic difference. pretty sure he meant double close ended pipes.

Yes thanks that's what I meant

 

[chiddler]

Huh...? Theres no such thing as double close ended pipes...

http://www.phys.unsw.edu.au/jw/flutes.v.clarinets.html#time

 

[chaser0]

Oh I see. i never heard of it before.