Phase difference and Standing waves vs Progressive waves

AI Thread Summary
The discussion centers on the confusion surrounding phase differences in stationary waves compared to progressive waves. It clarifies that between adjacent nodes, the phase difference is 0, while between odd-numbered nodes, it is π radians. The textbook's provided angles of 180, 225, and 0 degrees are questioned, as they seem more applicable to progressive waves. Participants emphasize the need for clarity regarding the position of points in the wave, particularly point B, which complicates the understanding of phase differences. The conversation highlights the conditions necessary for stationary waves to form, specifically the requirement of two progressive waves moving in opposite directions with matching frequency and wavelength.
Lamar Ngolo
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Homework Statement


Ok, so I am doing As physics at the moment and have been left confused by stationary waves.
I have read that between adjacent nodes/ even numbers the phase difference is always 0 and between numbers of does it is pi radians. So in the attatched image why is my textbook giving answers of 180, 225 and 0 degrees: this is what would be the case on a progressive wave, right?
Also, do stationary waves only form where 2 progressive waves in opposite directions have the same frequency, wavelength and constant phase difference, or only a few of the named conditions needed?

Thanks everyone

Homework Equations


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The Attempt at a Solution

 
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Lamar Ngolo said:
between adjacent nodes/ even numbers the phase difference is always 0 and between numbers of does it is pi radians.
That is rather garbled. Please clarify.

With regard to the question, I do not understand how you are supposed to know exactly where B is.
 
haruspex said:
That is rather garbled. Please clarify.

With regard to the question, I do not understand how you are supposed to know exactly where B is.
I was meant to put between odd numbers of nodes is the phase difference pi radians?
 
Lamar Ngolo said:
I was meant to put between odd numbers of nodes is the phase difference pi radians?
Ok.
In this question, O, A and C are antinodes, but the same method applies.
Counting from O, how many antinodes away is A? Is that an even or odd number?
How about from O to C?
 
haruspex said:
That is rather garbled. Please clarify.

With regard to the question, I do not understand how you are supposed to know exactly where B is.
haruspex said:
Ok.
In this question, O, A and C are antinodes, but the same method applies.
Counting from O, how many antinodes away is A? Is that an even or odd number?
How about from O to C?
Would it not just be Pi rad for A and B and 0 for C?
 
Lamar Ngolo said:
Would it not just be Pi rad for A and B and 0 for C?
π For A and 0 for C, but B is not at a node or antinode. As I wrote, from the information given, I don't know how you are supposed to know exactly where B is.
 
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