Sound Definition and 1000 Threads

Homework Statement A jet is flying horizontally [drawing shows an observer on the ground, a plane overhead at point B, and an outline of the plane from it's observed position to the left at point A. The angle between the observer and point A is 36°.] When the plane is directly overhead at B, a...

hello, i am involved in a private project. for this project it is necessary to control a huge amount of loudspeakers (intensity, frequency) in order to achieve beam forming of the sound waves. However, since i am not an electrical engeneer i really do not have a clue how something like this...

Homework Statement One microphone is located at the origin, and a second microphone is located on the +y-axis. The microphones are separated by a distance of D= 1.21m. A source of sound is located on the +x-axis, its distance from microphones 1 and 2 being L1 and L2, respectively. The speed of...

I am considering applying spray-on acoustic/popcorn ceilings to reduce the noise level in my house. I haven't found any data supporting that popcorn ceiling reduce noise level. I am looking for data, physics, experiments, and tools to help me figure this out. I asked this question at...

Homework Statement a noisy machine in a factory produces a decibel rating of 80 dB. how manyidentical machines could you add to the factory without exceeding the 90-dB limit? Homework Equations I=P/A and B+10log(I/I(sub)0) ... (I think) The Attempt at a Solution I tried to find...

Homework Statement http://dl.dropbox.com/u/11341635/IntegrationProblem.jpg Homework Equations http://dl.dropbox.com/u/11341635/Fourier%20Transform%20Equations.jpg The Attempt at a Solution http://dl.dropbox.com/u/11341635/1st%20part%20of%20attempt.png...

Homework Statement No specific question, I'm a greenhand to waves, so when it came to sound cavity, I was just confused how the teacher(in the video lecture,I'm not a physics major) can distinguish which side is a node and which is an anti-node, it seems too fast for me, could anyone give me a...

Homework Statement A jet is flying horizontally, as the drawing shows. When the plane is directly overhead at B, a person on the ground hears the sound coming from A in the drawing. The average temperature of the air is 20 oC. If the speed of the plane at A is 180 m/s, what is its speed at...

I'm doing a project on a water xylophone, and I have a couple questions about it. Please site your sources because we need all the help we can get. Thanks =D 1) How does the shape of the glass affect the sound the water produces. 2) Why does more water in a glass lower the frequency of the...

Thank you for the help!

Speed of sound The speed of sound c in a gas depends on among other things on the pressure on the gas, the density and probably, possibly on their viscosity. Determine c- My Variable list: Pressure p ML^-1T^-2 Density ρ ML^-3 Speed v LT^-1 My matrix: | | M | L | T | | p | 1 |...

wrt means with respect to Homework Statement see attachment that contains full question. firstly read paragraph then see on question. The Attempt at a Solution velocity of sound will be 340ms-1 wrt air or ground(since air i snot blowng). Now speed of soud wrt train A= speed of sound...

A submarine sonar system sends a burst of sound with a frequency of 325Hz. The sound wave bounces off an underwater rock face and returns to the submarine in 8.50s. If the wavelength of the sound is 4.71m, how far away is the rock face? (Ans: 6.51km ) -- v=fλ λ=wavelength f=frequency...

I would like to do some audio programming for a school project, but I'm not sure how a computer processes audio and reconstructs it in a sound card. I've had a signal processing course that covered standard DSP topics but I'm not sure when or how they are applied to acquire, store, and...

Knowing that its possible to break a glass if you emit a loud sound at its resonant frequency. If you do the same for Human skulls, there will not only be a sound sleep, but a sound death too. Is that possible?

hi i have a physics questions about sound Sound waves are used to detect faults in girders. a cro is used to detect these faults, a pulse producer and a detector is placed on opposite sides of the detector. The safe detector has a upwards spike at 0microseconds and at 10 microseconds. The...

[PLAIN]http://postimage.org/image/4ure9j3sr/1. Homework Statement i have a physics questions about sound Sound waves are used to detect faults in girders. a cro is used to detect these faults, a pulse producer and a detector is placed on opposite sides of the detector. The safe detector...

Homework Statement A jackhammer with a sound power of 10 W is operating in the countryside. Calculate the intensity levels at distances of 2.0 m and 50.0 m from the jackhammer. Calculate the corresponding levels in dB. Homework Equations β = (10dB) log (I/Io) where, β = sound...

A laser beam and a sound wave from directional sources both enter a liquid at an angle of 60 degrees from the horizontal surface of the liquid. The speed of sound in the liquid is 1.8 times that of the speed of sound in air. For light, the refractive index of the liquid is 1.8. What happens...

hi could somebody explain to me how organ pipes work? so far, i figured out that there are standing waves in an organ pipe, that are determined by the length and the question of whether there is a closed or open end. but what determines the intensity between these possible frequences(e.g...

Homework Statement In room temperature air, which of the following sound waves would have the greatest energy associated with it? A. A wave with lambda equal to 4.7 on B. A wave with a frequency of 2.6 Hz C. A wave which has a distance between adjacent nodes (1/2lambda) of 21mm...

I understand that an object can exist in many possible locations, and that when you're not looking, it is a wave. It's only when you look that it manifests itself into a particle. But Is that also dependent on the measurement of sound? Does an object materialize when you hear it, or feel a force...

What is the difference between sound and music? What is the basic property of music?

This is not a question as such, but it's for answering a homework question. I understand how stationary sound waves in a closed tube are formed, as they reflect off the closed end and the two waves traveling in opposite directions interfere to form a stationary resultant wave (that's how I was...

Amplitude Of Single Tone Sound Wave = "Loudness"? Hello, Given a single tone sound wave: x(t) = A * sin( 2 * pi * freq * t ), what does the 'A' actually represent? Peak Intensity? Intensity Level? Peak Amplitude Pressure? What is adding to my confusion is this link...

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

Not sure which section to post this in, but here goes. It's entirely my own words - might look like homework but it's for electronics. Multiple microphones are connected to a computer. A sudden sound, like a gunshot, goes off in the distance. These microphones are separated from each other by a...

If a sound frequency is given at 1800Hz, how can I determine what range of low frequency would create a harmonic or non-harmonic (which is opposite with harmonic) vibration with 1800Hz? Thanks in advance for any suggestions

A student typing in a computer cluster generates a sound level of 55 dB. What will the dB level the night before essays are due when there are 30 equally noisy students working in the cluster? dBo = 55 Ihearing = 1E-12 W/m2 Bo = 10log(I/Ihearing) 55 = 10log(I/Ihearing) 55 =...

Hello there, I'm making a presentation on the speed of sound in a few days and I was wondering if anyone knows where I can find a video that shows a (preferably huge) explosion from a distance with a timer on it. What I wish to convey from this video is the fact that the light from the...

Homework Statement You are standing in between two sets of railroad tracks. On one set of tracks a train is initially 200 m away and approaching you with a constant speed of v0 = 11 m/s. On the other set of tracks second train is at the same distance and moving away from you at the same...

Does anyone have any suggestions on what device can measure sound frequency below 20 Hz? Thanks in advance for any suggestions

When you try to listen to music through headphones you can reasonably hear the low end (lower frequencies). When you take the headphones off of your head and place them far enough away you only hear a tinny sound. When you are outside of a loud rock concert, maybe 1500ft from the source, you...

Hi, easy one but can't really get my head around it. The physics teacher today showed sound as Sine wave on an oscilloscope. If I was actually listening to this sound wave, where would it be silent, on the x-axis or at the trough? Please explain.

Does anyone know how to add more than two coherent sources that have different phases? An example might be a sound source and a receiver with sound reaching the receiver directly and by two reflections via different paths - maybe off a hard floor and hard ceiling. There's a good document...

I am trying to understand what the formula v=sq rt( Bulk Modulus/density). I understand that Bulk Modulus is indicative of a Pressure force and shows how much an object resists being compressed. So if we take a solid, it will have a greater Bulk Modulus than a liquid and so sound will travel...

My 2 year old play with the following toy at our home. https://www.amazon.com/dp/B000GKD006/?tag=pfamazon01-20 It is basically, when you put the correct animal block in the correct place, it makes the sound of that animal. I can see some sensor in the wood piece and in the board; it can...

Please solve showing all work asap thanks sooo much How many times more wavelengths occur in air than in water for an air temperature of 10 degrees Celsius if the speed of sound in water id 5220 km/hour and the frequency of sound is 500 Hz. Grade 11, thanks so much please ASAP

If water is hold inside the water bottle, which is made of plastic, and I play music within the room, can the sound vibration get through the plastic bottle and transfer it into water? Does anyone have any suggestions on what kind of materials to hold the water to get the best transfer rate on...

I'm looking for a 42" - 46" LED HDTV lately, and I keep looking at these TVs on sale that have incredibly low reviews and skipping over them. However, upon reading the "bad reviews" it seems everyone is saying "TV is fantastic, but the sound is bad." Here's just one TV for example...

Homework Statement Using the equation P=m/V show that the equation PV=nRT can become P/p=(R/MW)T P=pressure p=density of air n=number of moles of gas R=gas constant T=temperature m=mass V=volume MW=mass of one mole of air Homework Equations P=m/V PV=nRT P/p=(R/MW)T The Attempt at a...

When the wavelength is bigger than an obstacle, then the sound waves bend around the obstacle. so why I can't imagine this at all I read this page and watched the animations of it but it doesn't tell me the answer http://www.acoustics.salford.ac.uk/feschools/waves/diffract.htm reflection of...

I have done the hardware implementation using the planned schematic below. but somehow no sound seem to be able to play from the speaker except some noises. Anyone can help me check if something is wrong with DAC shematic...

Hi This is probably simple but i just can't seems to work it out: assume no gravity or friction: car 1 traveling at a constant speed of 50m.s in one direction Car 2 traveling at a constant speed of 50m.s on top of car 1 in same direction car 3 traveling at a constant speed of 50m.s on...

1. For this question, I need to explain why sound waves emitted into ocean water sometimes fail to give accurate results. 2.I have thought about, the salt density and the waves traveling through different water temperatures, but need to expand on these two ideas and don't understand it enough to...

Hello, I have read that vacuum cleaner makes 70 dBa and earplugs can easily go beyond this. The problem I have is that I can hear my neighbor's vacuum cleaner thru wall easily. But if I set my mp3 player at max (should be around 100dBa according to manufacturer) I can heard this at few...

I am taking a physics class and need to explain why we can hear better at night than during the day.

I understand the inverse square relationship between sound intensity (I) and distance (r). There was a misunderstanding in physics class today about the mathematical and theoretical relationship between sound intensity and power according to the equation: I = P/4∏r2 Sound intensity is...

Why can't sound pass through closed doors?

How is sound able to be transmitted through the air with such extreme clarity. What I find puzzling is that air has no stiffness to it at all. There are just countless numbers of molecules traveling at the speed of sound in random directions. How can a single speaker cone set up pressure...