Sound Wave Diagram Help

[newtonphysics]

Homework Statement

Two speakers are positioned facing each other 16m apart.
Draw a diagram representing the compressions (whole lines) and rarefactions (dashed lines) of sound waves radiating outwards. Mark several areas of constructive and destructive interference.

Relevant Equations

sound waves

I have tried to draw the diagram and would just like feedback on it to know whether it is correct or not.

Please keep in mind this was done roughly. Thanks

 

[kuruman]

How about explaining what the colored dots mean? It's your diagram, no?

 

[newtonphysics]

How about explaining what the colored dots mean? It's your diagram, no?

blue dots are constructive interference and red dots are destructive interference. I just realised that there should only be two colors of dots and not three. Assume green dots are also red.

 

[nasu]

Are the speakers supposed to be out of phase?

 

[newtonphysics]

Are the speakers supposed to be out of phase?

they are coherent

 

[nasu]

Coherent means that the phase difference is constant. Any constant. Your drawing seem to assume a phase difference of 180 degrees.

 

[newtonphysics]

Apologies for the misunderstanding. Yes they are out of phase

 

[kuruman]

blue dots are constructive interference and red dots are destructive interference. I just realised that there should only be two colors of dots and not three. Assume green dots are also red.

Solid lines are compressions, OK.
Dashed lines are rarefactions, OK.
It follows that solid and dashed lines are 180° out of phase.
Does it follow that at the green dots, where two dashed lines are superimposed, you should have a red dot instead indicating destructive interference?

 

[newtonphysics]

Solid lines are compressions, OK.
Dashed lines are rarefactions, OK.
It follows that solid and dashed lines are 180° out of phase.
Does it follow that at the green dots, where two dashed lines are superimposed, you should have a red dot instead indicating destructive interference?

thanks for your help

 

[kuruman]

thanks for your help

You are welcome. How about posting a revised figure for the benefit of anyone who might come across this thread in the future?

 

[nasu]

If they are both dashed they are in phase. Half a period later the same point will be reached by two solid lines. The amplitude of the pressure at the point has maximum value. At the constructive interference there is maximum rarefaction too.

 

[newtonphysics]

You are welcome. How about posting a revised figure for the benefit of anyone who might come across this thread in the future?

Great suggestion. I shall do that. Quick question though ... how do i find the second intensity minimum and use it to calculate path difference from the centre?

 

[kuruman]

I am not sure what you mean by "second intensity minimum". As for the "path difference from the centre", at any point you have two intersecting radii representing the path from the centre of each source. Isn't the difference between the two the "path difference"?