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# Particle longitudinal wave watch

1. Where is the point Q going to move as the wave moves right?

The answer is left but I don't see what could indicate so bearing in mind this is a 1 mark question so it should be a simple method to predict this. Anyone able to shed some light on being able to predict the movement of a particle as the wave propagates. I can see that the point Q is slightly to the left so this would indicate it is going to move to the left but is this correct?
2. Isn't it that longitudinal waves have vibrations of particles that move in the same direction as the wave is travelling but the rarefaction is like a spring so would be the opposite?

And transverse are at 90 degrees to the wave direction

Not sure but it might be what you are looking for
3. (Original post by Xenon17)

Where is the point Q going to move as the wave moves right?

The answer is left but I don't see what could indicate so bearing in mind this is a 1 mark question so it should be a simple method to predict this. Anyone able to shed some light on being able to predict the movement of a particle as the wave propagates. I can see that the point Q is slightly to the left so this would indicate it is going to move to the left but is this correct?
They oscillate back and forth without traveling with the wave , being displaced and then returning to their original position?
4. (Original post by leavingthecity)
They oscillate back and forth without traveling with the wave , being displaced and then returning to their original position?
(Original post by brainzistheword)
Isn't it that longitudinal waves have vibrations of particles that move in the same direction as the wave is travelling but the rarefaction is like a spring so would be the opposite?

And transverse are at 90 degrees to the wave direction

Not sure but it might be what you are looking for

I'm not stupid I'm looking for the method of predicting the movement of a particle as the wave propagates this is easy for a transverse wave
5. (Original post by Xenon17)
I'm not stupid I'm looking for the method of predicting the movement of a particle as the wave propagates this is easy for a transverse wave
Apologies if I offended you, this isn't something I know. I will look into it. Sorry.
6. (Original post by leavingthecity)
Apologies if I offended you, this isn't something I know. I will look into it. Sorry.
No need to apologise. I've been looking into it for a while and the closest I could get is this which still doesn't allow me to predict where that point Q is going to move just as the wave moves right
7. (Original post by Xenon17)
I'm not stupid I'm looking for the method of predicting the movement of a particle as the wave propagates this is easy for a transverse wave
Likewise I am sorry if this is an insult to your intelligence - this is all I know and I was trying to be helpful
8. I have found this, I am reading through it, have not finished and it will take me longer to get my head round than you because I am completely self taught, but here you go, let me know if it's relevant. There is a lot to read. It discusses how mass movement along a longitudinal wave is derived from an equation for transverse waves where downward and upward movement are replaced with leftward and rightward movement respectively and this time all in 1D, where mass density along a straight line can be derived from the slope of a 2D transverse wave.

http://www.people.fas.harvard.edu/~d...ngitudinal.pdf
9. (Original post by leavingthecity)
I have found this, I am reading through it, have not finished and it will take me longer to get my head round than you because I am completely self taught, but here you go, let me know if it's relevant. There is a lot to read. It discusses how mass movement along a longitudinal wave is derived from an equation for transverse waves where downward and upward movement are replaced with leftward and rightward movement respectively and this time all in 1D, where mass density along a straight line can be derived from the slope of a 2D transverse wave.

http://www.people.fas.harvard.edu/~d...ngitudinal.pdf
I have found the answer

The behaviour of point Q is more difficult to understand. The particle changes direction whenthe centre of a rarefaction or compression reaches it. If the wave is moving to the right, then as thecompression gets closer to the particle, the particle will move left towards the compression
10. (Original post by brainzistheword)
Likewise I am sorry if this is an insult to your intelligence - this is all I know and I was trying to be helpful
(Original post by leavingthecity)
I have found this, I am reading through it, have not finished and it will take me longer to get my head round than you because I am completely self taught, but here you go, let me know if it's relevant. There is a lot to read. It discusses how mass movement along a longitudinal wave is derived from an equation for transverse waves where downward and upward movement are replaced with leftward and rightward movement respectively and this time all in 1D, where mass density along a straight line can be derived from the slope of a 2D transverse wave.

http://www.people.fas.harvard.edu/~d...ngitudinal.pdf

So I had some free time to think about and basically you guys probably wouldn't have noticed it either because I missed out that this was a slinky. Basically the trick to answering this 1 marker in 10 seconds is that as the longitudinal wave propagates to the right the region of compression moves to the right and thus this means the point Q moves to the left. Idk how I didn't see this but I guess it pays to always read the information given.

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