How is longitudinal wave spread

[zade70]

Homework Statement

How is longitudinal wave spread?
http://s11.postimg.org/pm7hxibo3/vala.png
Here is how the transverse wave is spread in T/4, T/2, 3T/4, T (T- period)
I need the same graph for the longitudinal wave.

Homework Equations

X=c*T (c-velocity of moving of the wave)

The Attempt at a Solution

https://www.google.al/search?q=long...KHW--DHkQ_AUIBygB&dpr=1#imgrc=NCmiLxCD1edSYM:
In this picture it is shown a longitudinal wave. How can I show how it is spread in T/4, T/2, 3T/4, T? Where will the rarefaction and compression be in different times?

 

[BvU]

Same graph, only arrows go left-right instead of up-down. See e.g. here

By the way, you call that 'propagating', not 'spreading'.

And yes, rarefaction (valley) will be T/2 after compression (peak), just like in a transverse wave + maximum and - minimum are T/2 apart in time.

Similarly, rarefaction (valley) will be $\lambda$/2 behind compression (peak), just like in a transverse wave + maximum and - minimum are $\lambda$/2 apart in distance.

 

[zade70]

Same graph, only arrows go left-right instead of up-down. See e.g. here

By the way, you call that 'propagating', not 'spreading'.

And yes, rarefaction (valley) will be T/2 after compression (peak), just like in a transverse wave + maximum and - minimum are T/2 apart in time.

Similarly, rarefaction (valley) will be $\lambda$/2 behind compression (peak), just like in a transverse wave + maximum and - minimum are $\lambda$/2 apart in distance.

http://s30.postimg.org/igw0ava9t/vala1.png
I caught some moments from a video. Is each picture T/4, T/2, 3T/4, T? If no could you please draw it correctly? Thanks

 

[zade70]

I tried to do it. Is it correct? If yes, could you tell me where to put the other arrows (I haven't completed all the positions with them. http://s17.postimg.org/wcr8m3tnj/image.png

 

[BvU]

Would you please first render the litteral problem statement ?
And: what relevant equations do you have to represent graphically ? $X = ct$ is a straight line...

 

[zade70]

Would you please first render the litteral problem statement ?
And: what relevant equations do you have to represent graphically ? $X = ct$ is a straight line...

I haven't got any equation to represent. I just wrote it because it is necessary to writ an equation related, but it has nothing to do with the solution. I just want the longitudinal wave spreading graphic

 

[haruspex]

I tried to do it. Is it correct? If yes, could you tell me where to put the other arrows (I haven't completed all the positions with them. http://s17.postimg.org/wcr8m3tnj/image.png

I find that drawing very hard to interpret.
I suggest starting with the diagram you first linked, showing a spring with various sections of it under compression and tension. You could try adding arrows of different lengths and directions to that, illustrating which parts are moving forward fastest etc.
To help construct that, you could make a second copy of the spring picture underneath and shifted a bit to the right, thereby showing where everything will be a a short time after the first picture.