Sound Definition and 1000 Threads

If you seal a loudspeaker at the end of a tube and close the other end of the tube you will get standing waves; but what are the boundary conditions at the speaker for the sound pressure wave? Pressure =0 or Pressure = MAX? I find no mention of this in the literature. To find out I performed a...

What causes to produce sound (like boom) when crossing a sound barrier. With regards Nilesh.

A. Sound is nothing more than a local disturbance whose propagation is facilitated by the collisions between particles B. The distances between molecules in solids are very small, i.e., solids are more dense - as compared to liquids and gases. Because they are so close, than can collide very...

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > Last week we had to conduct an experiment with the aim of determining the speed of sound. I decided to play with doppler effect. I was more or less sure what I had to do but then the teacher came...

Dear all, I have been attempting to create a range of bamboo flutes with different lengths for my physics practical. I am trying to calculate the theoretical frequency that should be produced by a particular length of flute, but all my flutes have different diamaters and I am searching for an...

my question is just that how does the wavelength and frequency of sound wave change when it travels from rarer to a denser medium ....... and whatever is your solution please give a briefer insight into it.. NOTE: i was recently going through a physics olympiad paper and i found from a...

I recently read about the recommended amount of exposure time to high sound volumes: http://www.dangerousdecibels.org/education/information-center/decibel-exposure-time-guidelines/. Since I am in the Band at school I was somewhat concerned about if the sound intensity would be too much...

Homework Statement Fans at a stadium produce sound that is heard 1km away, the intensity level is 60 dB. How much acoustic power is generated by the fans? Homework Equations B = 10 log (I÷I_0) P=I*A The Attempt at a Solution I= 10^-12*6^10= 10^-6W/m^2 P= 10^-6*4pi*1000^2 =12.56W However...

Today I was presented with dispersion in my introductory physics class. Before this topic was presented we were told of two important rules for waves: 1) The speed of a wave is dependent on the medium in which it travels and 2) the frequency of wave does not change when going from one medium to...

Homework Statement The human beings are standing at equal distances from a big and high wall. Distance between them is 150 m. When one fires the gun the other hears two shots in an interval of 2 seconds, using the speed of sound to be 340.298 m/s calculate their distance to the wall. Homework...

Hi guys, I am new to the forum and I have what is probably a simple question for most of you. Unfortunately a great deal of people I know have suddenly taken up the idea of a "Flat Earth", and they consistently post things that try to contest that a flat Earth is a far more logical idea than a...

Homework Statement ___ In 1866, the German scientist Adolph Kundt developed a technique for accurately measuring the speed of sound in various gases. A long glass tube, known today as a Kundt's tube, has a vibrating piston at one end and is closed at the other. Very finely ground particles of...

Apologies if this is a stupid question, I have a reference that says: "An ultrasonic field will be a combination of standing and traveling waves. An increase in the traveling wave will decrease the proportion of a standing wave and vica versa". I'm trying to visualise this, I understand the...

... it's amplitude exerts. During cavitation a sound wave is applied to a liquid and breaks it apart and gas pockets are formed. The frequency and the amplitude of the sound wave effect the bubble/s. My question is, if I have the power output of the device then how would this relate to the...

Hi, I'm writting a program in the computer and I've to perform a fast Fourier transform to get the frequency domain information. I've read different website, I've watched some videos, etc and I don't fully understand the whole theory about FFT. I've to say that I don't have a solid mathematics...

I want to purchase the Logitech z623 and add to it two creative inspire M2600 speakers (only the speakers, not the sub-woofer). The reason for doing this is because the Logitech system sounds really nice, it has an amazing bass, but mids and highs are not the best and I wish they was as clear as...

Good day (or night). I am new here, so I hope my question doesn't bother many. If (forgetting other laws of nature) a shoebox where to hit the sound barrier and an F-35 were to do the same. Would the sound waves be equal. Would it sound the same to a ground observer? I always assume that mass...

I was watching 'The sound of Music' for the nth time with my 11 year old daughter. There is a scene at the beginning, the Reverend mother tells Maria to go to the Captain's house. My daughter insists the reverend mother says "the captain's wife died seven years ago". And when the kids's names...

Does the ability of an observer to hear a sound wave depends solely upon the intensity of the sound wave?

Shock wave is caused by the disturbance of air by the airplane. When it propagate the mechanism should be the same as that of longitudinal sound wave. Why sometimes it can travel faster than sound? (also see: http://physics.info/shock/ )

So I'm sitting on a happy GPA and an acceptance letter to transfer to a nice school for the rest of my undergrad, my dreams of a PhD looking bright, and this terror just grips me like a swimsuit out of water. I've never actually talked to a professor about how research works. I've read a lot...

I know this is speculation but, if the inner solar system was permeated by a gas which could transmit sound waves (say for simplicity, similar to air), would we hear the Sun burning? And which kind of sound would it be? Which timbre and range of frequencies? Would it be unbearably loud? Or very...

As far as I know sound is vibrating matter. Does that mean it could not exist in a vacuum? In outer space there is much less matter for sound to interact with so my question is, how does a sound generated in high matter places change as it travels to low matter places? For example, if you...

Like spacetime , can sound be taken as a fifth dimension?

Hi, As far as I know the speed of sound is also constant irrespective of the speed of the source. I guess, this is an obvious result of the property of waves. So, why is the constancy of speed of a light wave more important? Please point out if there are any mistakes in my assumptions.

After supernova explosion sound is created... so what happens to that sound??

I lightly placed my finger a quarter of the length down the E-string of a violin and drew the bow, forcing the third harmonic. I used an oscilloscope app to look at the waveform. I got this unusually regular pure pattern...

Homework Statement A public-address system is usually used in the school assembly to obtain better attention from students. Carry out a study on the factors affecting the audibility of sound. Homework EquationsThe Attempt at a Solution Objective: To study how does the frequency of the sound...

Dear PF Forum, Sorry I ask this. I should have googled it or doing the experiment myself. :smile: If a cars runs 50 m/s and at that time fires a missile, the speed of the missile is 100 m/s so the total speed of the missile is 150m/s, is this right? And if we sit at the back seat of an airplane...

Homework Statement A sound source is placed at the top of a tall (h = 189.6m) radio tower. The source has a frequency of 740 Hz and an amplitude of 19.4 nm at point A. The air surrounding the tower has a density of 1.29 kgm-3 and sound travels through it with a velocity of 343 ms-1. Point A is...

When a loudspeaker moves back and forth, sound is generated. The moving of the loudspeaker diaphragm causes condensation of air when it moves outward, and rarefaction of air when it moves inward. When this movement is happening at a certain frequency, we hear a sound. See for example this...

Homework Statement A sound source is placed at the top of a (h = 121.5m) radio tower. The source has a frequency of 653.8 Hz and an amplitude of 11.4 nm at point A. The air surrounding the tower has a density of 1.32 kgm-3 and sound travels through it with a velocity of 340 ms-1. Point A is...

http://www.quora.com/How-can-sound-waves-alter-the-flow-of-water Ok, so I carried out this experiment, and I understand some of it, but need help with other parts. Ok, so are we actually seeing a sine wave formed by the water? If so, I understand that waves are supposed to transport energy...

If you have the same liquid, water, but with different ions dissociated in it, changing it's colligative properties, does the index of refraction change? And/or does the speed of sound through it change?

School's done, and I'm in the middle of summer break, so I've got time to worry about things like this. (Y) I moved to a town 30 minutes from Toronto when I was 2, and have lived here ever since. I was born in Korea, but I thought that I sounded like any other Torontonian. Nope, there's...

Problem: A swimmer sees a parachutist hit the water and hears the impact twice, once through the water and the second time through the air, 1.0s later. How far from the swimmer did the impact occur. Vs of air is 340m/s. Vs of water is 1400m/s and the answer in the book is 450m. 2. I know this is...

Homework Statement Calculate the room temperature by using the speed of sound formula and using the given values. Known Data: Frequency = 480 Hz 2nd Resonant length = 54cm or 0.54m Homework Equations v = 331 + (0.60)T T = (v - 331)/0.60 v = fλ (Open-Closed air column) L = (3/4)λ The...

The venturi effect of the new ARX bullet almost doubles side exit velocity. What happens if the exit velocity exceeds the sound barrier in a fluid like a gelatin block?

Homework Statement Why is is that when we look in a mirror we expect to see a reflection equally as bright as the real image, but when we stand in front of a cliff and clap our hands we don't hear an echo as loud as the original sound? Homework Equations R = (z2 - z1)/(z2 + z1) The Attempt at...

So we all know that the speed of sound increases with greater density of medium. Conversely, the speed of light decreases with greater density of medium. Does there exist such a medium that is so dense that the speed of sound overtakes the speed of light?

I've been researching this subject for a little while. I'd like to hear your ideas, because the topic is widely discussed. So here is some part of my research which makes my opinion quite clear: "Sometimes we say , that one is moved by music. Of course, it does not mean for him/her to be...

I had a physics course a few years back that touched on constructive and destructive waves and only today did i notice this phenomenon with my speakers. I was curious about the theory behind this particular scenario in my room. I have one of those mobile speakers, a bose soundlink II. It has 4...

Homework Statement Two loudspeakers on elevated platforms are at opposite ends of a field. Each broadcasts equally in all directions. At the halfway point, the intensity is 74.1dB. What is the sound intensity level at a point one-quarter of the way from one speaker to the other along the line...

I have 2 types of sound reflectors on the image attached. The angles are not proportional but you should get the idea. The black circle is the source, the black lines are the waves and the red lines are the reflections of the waves emitted by the source. My target is to reflect the sound waves...

I would like to be able to measure the distance a sound wave travels. This is for a violin bridge and what I would like to do is apply a frequency corresponding to the frequency the string (196 hz for the g string) and determine the distance the wave traveled to get to the foot of the bridge...

Homework Statement If you hear music in the distance, would you be more likely to hear the treble or the bass notes of the music? Using your knowledge of diffraction, explain your answer. 2. The attempt at a solution So I found that the bass's waves are carried at a longer distance than the...

I guess that the way we experience sounds on Earth is very importantly influenced by the composition and density of our atmosphere, since it determines how a pressure wave will be formed and will propagate. Does music sound appreciably different when heard at very high altitudes with low air...

Could you tell me the physical reason, why the absorptive type sound insulation (Windowpane with some thickness) is effective only at high frequencies of sound source?

Homework Statement A family ice show is held at an enclosed arena. The skaters perform to music with level 80.0 dB. This is too loud for your baby, who yells at 75.0 dB. (a) What total sound intensity engulfs you? Homework Equations I ∝ A2 The Attempt at a Solution Why did the answer sum...

Homework Statement A student enters Best Buy prepared to buy a pair of speakers. Before he does so, he conducts an experiment with them. He places the speakers 4.0 m apart and connects a signal generator to both speakers that produces a single and consistent tone. (constant wavelength and...