What's the relationship between the amplitude and the Sound power level?

AI Thread Summary
The discussion centers on understanding the relationship between sound wave amplitude and sound power level. It clarifies that sound waves are pressure variations in a medium, and amplitude can be related to sound pressure levels. The conversation emphasizes the need to translate wave displacements into pressure measurements for accurate assessment. A microphone is cited as a tool that measures changes in air pressure, which is essential for understanding sound levels. The participant expresses gratitude for the clarification and acknowledges the need for rest to process the information.
MrMeltedChees
Messages
3
Reaction score
0
Okay, so I have a sound wave (a visual representation). From this I can see the amplitude of the wave, However, I need to know what the sound power or the sound pressure level. Could someone please give me a formula that could help?
Thanks
 
Last edited:
Physics news on Phys.org
You are asking something quite complex and your terms suggest you are not clear about what is going on.

A sound wave is usually thought of as pressure variations in some fluid like air - though it can also be vibrations in a solid. So the wave itself is the pressure level - though you may have a description of it in terms of longitudinal displacements, in which case you need to translate the displacements into pressure.

A single note would give you a sinusoid with a constant amplitude. The magnitude of the wave may vary with position and with time for a fixed position.

The wave can also be represented in terms of energy - the parts where the medium is moving most has the most kinetic energy for example.

So before you start, you need to know what it is that is being measured.
A microphone, for example, measures changes in air pressure.

Possibly what you are looking for is something like this:
https://www.physicsforums.com/showthread.php?t=544248
 
You're right, I had no idea what I was talking about.
Thanks for the info, that really cleared things up. That link wasn't exactly what I was looking for, but I understand it all now. I guess all I needed was some sleep. Thanks a bunch anyways.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top