Sound Definition and 1000 Threads

Hi - I am a lay person with a practical question regarding sound. I live near a busy street and am considering having noise-reducing windows installed. The noise-reducing windows would fit beside (and in addition to) the current window to block out street noise, so in effect there would be two...

Hello, I'm calculating a physics problem and I'm supposed to calculate the height of a building given that: rock is dropped from the building, the sound of the rock hitting the ground is heard 4.8s later, the speed of sound is 350m/s, and I don't know how do I calculate the time since...

If you visualise in terms of what it actually is (colliding molecules), what would the wavelength, frequency and amplitude be? I think for amplitude the molecules are hitting each other harder, but wouldn't that mean they're moving faster as well?

Homework Statement http://insight.ccsf.edu/file.php/4599/PDF/Exam1-Fall-2011.pdf Homework Equations v^2=T/μ κλ=2∏ ω=2f and many more The Attempt at a Solution Starting with 1a the λ is 4/3*.015cm=.02cm since by the diagram the distance between the labeled point is 3/4 the...

If I am stationary and a sound source moves towards me at a constant velocity, I will hear it (the sound) increase in frequency until it is adjacent to me and then as it moves away from me, I will hear a decreasing frequency. Fundamental stuff right? It works with radio waves and light which is...

Homework Statement a submarines sends sound waves and receives it after 4 seconds then goes under water 700 m and sends waves and receives it after 3 seconds he wants the depth of water Homework Equations V=d/t The Attempt at a Solution V=d/t V=x/2 then V=X-700/1.5 so x/2 =...

Homework Statement One of the 63.5-cm-long strings of an ordinary guitar is tuned to produce the note B3 (frequency 245 Hz) when vibrating in its fundamental mode. A) Find the speed of transverse waves on this string. B) If the tension in this string is increased by 1.0%, what will be...

I am thinking about upgrading my soundcard from the creative soundblaster fatality X-Fi to the new creative SB fatality X-Fi Recon-3D. Is this upgrade worth the money? Will I notice an improvement in sound quality? What is the benefit of a quad-core audio processor? How is the X-Fi Recon-3D...

Hai, I have a material related question. I am working with polymeric materials (Poly carbonate's and PMMA's respectively) which have to be tested for impact resistance (at high velocities). It came to my mind if the impact process could be correlated to a sound based measurement. Now i want...

Homework Statement Two identical loud speakers placed at A and B 2m apart produce sound waves of frequency 440 HZ and with a velocity 320 m/sec a small microphone was used and placed at C along a perpendicular line from AB if there will be a destructive interference at C find the length of...

Here's how I understand the situation: when an electrical current is running through a wire, the individual electrons are moving very slowly. The reason that a light bulb turns on so quickly after the switch is closed, then, is because as the electrons near the switch start moving, they push on...

When water is flowing out of the tap, there is a buzzing/hissing sound. I can hear One sound coming immediately out of the tap and the other sound when water hits the ground. What are the reasons for these different sounds. Can someone explain to me in layman terms. Thanks.

Homework Statement A choir made up by 100 voices (i.e. 100 singers), during the execution of a song, reaches the sound intensity of 100dB. Assuming that all singers sang with the same intensity, the sound intensity of each singer was...? Homework Equations ΔS=10.log(I/Io) The...

I am not sure if this is wright section for this question,so please excuse me if a made a mistake. I am thinking of witing a paper about air as a meaning of sound transfer.Does humidity,temperature etc.influence sound.It should consist experiments and theory.So could you recommend me good book...

Homework Statement Sound Wavelength From String During a concert a pianist hits a key that sets up a standing wave in a piano string that is vibrating in its fundamental mode. The string is 0.5 m long, has a mass density of 0.002 kg/m and is held under a tension of 120 N. What is the wavelength...

If an object of VERY high mass were to hit a hypothetical wall at a high velocity and the wall somehow withstood that, what would happen to you if you were standing on the other side close to the wall but not touching it? Would there be some sort of wave transmitted through it? If so, would this...

Why sound waves propagate through liquids as longitudinal waves, and it is propagate on the surface of the liquid as transverse waves?

If a basic sin sound wave is analysed with a Fourier transform, the result is just a spike at a certain frequency. My maths isn't the best so bare with me... if we take a real sound file and take Fourier transforms at regular intervals (I assume that's what's being done when calculating a...

Sorry for another dumb question. Thank you in advance. What factors effect the frequency of sound and light waves. Light waves are effected by electromagnetic energy and given by (f=E/h) right? What about sound waves? Also, to make sure, even though ultraviolet light has much more...

hello guys, I'm having problems understanding why if we were to have a tuning fork that vibrates at a particular natural frequency, it will resonate at many different lengths of air column (which means different natural frequency of air column). Does this mean that the natural frequency of the...

I have two different sound sources (suppose two different person's voice playing in different volume). How to find which sound coming from further distance. What is the exact equation to calculate distance.

Homework Statement A car is driven at 30m/s between two sources, each producing sound waves of 1.50x10^6 Hz. The sound heard by driver rises and fades as he travels from one sound source to the other. Find the period of regular fading. Homework Equations No relevant equations...

Hey, I'm just curious if anyone has designed a device that can direct and concentrate sound waves like a parabolic mirror? Since both sound and light are waves, I assume there must be a shape that allows one to "target sound" much like using a magnifying glass to focus light. On a related...

Hi everyone! I was reading a textbook a while ago about waves and it had just finished talking about wave speeds and how it is the product of the frequency times the wave length. On the next page, it gave a table of frequencies and wave lengths of sound waves and how their products are all...

Homework Statement The intensity of a sound wave at a fixed dis- tance from a speaker vibrating at 1.31 kHz is 0.894 W/m^2. Determine the intensity if the frequency is increased to 2.33 kHz while a constant dis- placement amplitude is maintained. Answer in units of W/m^2 Homework...

Homework Statement How do you calculate the speed of sound in water at 16 degrees celsius? Homework Equations Speed at 20 degrees is 1482m/s The Attempt at a Solution I need help getting started... I don't know how to go about trying to work this out (this isn't a homework...

When an object is thrown out from the front of a vehicle, its initial velocity relative to the ground is the velocity relative to the vehicle plus the velocity of the vehicle. Why is this not the case with sound traveling out from the front of a jet for instance? Or do the velocities add...

Why can't we see sound waves?

Hi, I've been trying to look up the effects of density and humidity on the speed of sound, and I've been finding conflicting results. Some websites have stated that increased humidity will increase the speed of sound because of decreased density in the air, but wikipedia's speed of sound article...

Homework Statement A pair of speakers connected to the same signal generator face each other, one at x=0 and the other at x=1.5m. If they are producing a sound frequency of 2000Hz what are the points (position x) of constructive interference between the speakers? Express your answer in...

Homework Statement Consider two sources of sound, each of which emits a sound wave of the SAME frequency and the SAME intensity. The sources are located on a straight and level road, relatively close to each other. You, the listener, are also located on this road, about 1/4 mile away from the...

Our backyard backs up to a major freeway u need hear protection to stand at the back gate for to long we r less then 20 feet from the edge of the road id like to turn this extreme noise into usable energy... is there anyway to convert it into electricity or use some kind of aperatise to convert...

Speed of sound at a specific temperature is independent of Pressure as Pressure varies directly with density. So wouldn't any change in density vary the pressure such that it has no net effect on speed of sound? but my book says the speed increases with decrease in density...

Homework Statement Singer sings middle C. She then gulps helium and tries to sing the same note i.e her vocal chords remain the same. What note will the listener hear? Homework Equations f=velocity of air/lambda middle C The Attempt at a Solution f=velocity of air/lambda...

Why doesn't Sound depend on pressure while depends on Humidity ?

Homework Statement The Attempt at a Solution I don't understand where that 2 comes from in the denominator in cos nπ/2

I'm trying to understand how to use the special relativistic sound formula for a perfect fluid : c_s = c \, \sqrt{\frac{dp}{d\rho}}, where p is the isotropic pressure and \rho is the total energy density (not the internal energy density \rho_{int} or mass density \rho_{mass}). In the case of...

Why do low frequency sounds (like low bass notes) disperse omni-directionally, whereas high frequency sounds are much more directional? Also is there a formula that governs this?

This is from Paul Davies the Last Three Minutes I thought sound is due to particles moving up and down which activate hairs inside our ear which our immaterial, nonphysical, unconscious mind converts into meaning and communicates that meaning to the conscious mind. I don't see how the...

effective sound power from cube if there was a sound source that radiates equally in all directions in a cube enclosure, and the cube was completely absorbative, how would you tell how much sound is coming out of a small gap in one of the walls and find the effective sound power of the cube...

Apparently, there is a limit to the maximum sound amplitude that depends on the medium in which the sound in question travels. In the atmosphere, the limit is supposedly around 194 Db, arising from the fact that in sound above this level, the pressure throughs would exceed atmospheric pressure...

Polly the parrot wants to escape from her enclosure at the zoo. The enclosure has a glass door and by tapping on the door with her beak Polly has been able to determine that the natural resonant frequency of the door is 900 Hz. The highest frequency squawk Polly can muster is 850 Hz but at one...

i was wondering that can the speed of sound be lowered than the normal 335m/s in air without changing the air conditions? let's say u spoke in a low voice, will the sound still travel at 335m/s? will all air waves travel at that speed. no matter how weak or strong they are?

I was considering the following question; 'A fire engine traveling at 70m/s drives past a van traveling at 30m/s. The speed of sound in air is 330m/s and the fire engine has a frequency of 200Hz when stationary. At what frequency does the van driver hear the siren?' I understand you have...

Homework Statement http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20%289702%29/9702_s09_qp_2.pdf number 5b The speed of sound is 330ms-1 The frequency of sound from S1 and S2 is increased. Determine the number of minima that will be...

I know that light can, because otherwise black holes wouldn't exist. But can sound fall? And are there any effects caused by this. By doing a rough calculation, if sound could fall, sound would have a maximum vertical range of about 5km. Do we see this in real life?

Hi. I noticed that my phone charger (output: 5V DC) makes a constant high pitched noise when plugged into the wall. It's not too loud but you can hear it when you are within maybe 4 ft of the charger. When I plug my phone in, it starts making intermittent noises. I was wondering what this could...

When a car is approaching it has a higher frequency and shorter wavelength. When it has passed sound waves are a lower frequency due to a longer wavelength. Question: Does the higher frequency contain more energy when compared to the low frequency? IF IT DOES NOT, then could it possibly be...

Homework Statement The sound intensity level of a certain sound source is measured by two listeners located at different positions along a line from the source. The listeners are located on the same side of the source and are separated by 34.8 m. The listener that is closest to the source...

Homework Statement A brother and sister try to communicate with a string tied between two tin cans. If the string is 9.5m long, has a mass of 55g and is pulled taut with tension 6N, how much time does it take for a wave to travel from one end of the string to the other? Homework Equations...