Sound Definition and 1000 Threads

Homework Statement Suppose a harp string is tuned to middle C (C4) and is 0.56m long. If I want the tension to be 193.5 N, what mass per unit length do I need the harp string to be? Calculate your answer in kg.m Homework Equations Vs = sqrt(T/μ) V = fλ The Attempt at a Solution Having a very...

Homework Statement Two trains approach the train station from opposite sides each moving at an initialvelocity of 120 km/h with respect to the station and slowing down to a halt in 20seconds. If both trains are whistling at 5000 Hz, find the distance between the zeroand first order maxima as a...

So I'm trying to understand how the modulus works in metals. I understand that when the temperature rises, that means that the modulus decreases. But I do not understand exactly what it is or how it affects the way that the molecules would vibrate for instance, as kinetic sound energy moved...

Homework Statement Suppose a spherical loudspeaker emits sound isotropically at 10 W into a room with completely absorbent walls, floor, and ceiling (an anechoic chamber). (a) What is the intensity of the sound at distance d = 3.0 m from the center of the source? (b) What is the ratio of the...

Homework Statement Two kids are positioned as in the following figure and A emits a long sound. d=100m, x=40m, vsound=340m/s How long (t) does the sound emitted by A has to be such that B perceives a signal that lasts 2t? Homework Equations [/B] The Attempt at a Solution [/B] Seems like...

Hello, excuse me if these happen to be basic questions, but I'm a psychologist/neuroscientist in training without any particular experience in physics, and I am just confronted with a very specific problem. I need to measure the sound pressure experienced inside of an MRI scanner...

Sound pressure waves attenuate pretty quickly. On Earth we can not hear much of what is going on a few kms away, or above, or underground, unless it's some really catastrophic event of huge energy. But the Sun's energy output is hugely immense compared to even the most catastrophic event on...

Hello, a certain sound remains in our brain for 1/10 of a second. The phenomenon of echo can happen only if the distance is at least 17 meters: we say the letter A, which remains in our brain for 1/10s, and the reflection (echo) of A arrives to our ear after that 0.1s...If the distance is...

Hello, Sound waves are always introduced as longitudinal mechanical waves: the medium particles oscillate in a direction parallel to the direction of motion of the sound wave. We can only hear sound frequencies between 20Hz and 20KHz. For us to hear these mechanical sound waves, the waves need...

When we unfill a waterbottle, we here a periodic sound like- cloc.. cloc.. cloc..- How does this happen?

I was wondering if sound underwater traveled further than sound in air? It seems like it wouldn't do to viscosity. I know that it travels faster however. Lastly, is the online reasoning for why we can't hear sound as well underwater correct: the water vibration bypasses some of the sensory...

I have 3 question: 1) How whistle produces a sound? I mean sport whistle with small ball inside. 2) How we whistle (by mouth)? 3) If you have a hole in exhaust tube in car. Many people say to me: "It is louder when the car drove long time. (a tube is hotter)" My easy question is, why? And what...

Hello everyone, First of all I am new here~ Second, I would like to "prove" on COMSOL that soundwaves (sound vibration) can alter/reshape the fluid flow Can someone tell me the physics i should use as well as all the other parameters to make it work? if someone is more experience can they...

Small caliber guns have higher magnitude at higher frequencies and larger caliber guns have higher magnitude at lower frequencies. is this true ? because I am not see this in my test: that is the fft of a 9MM gun, As one can see there are low magnitudes at low frequencies and higher...

Hello! First time posting here. I'm studying the IB and need to complete my required experimental write-up. I am looking to replicate the well-known experiment that finds the value of g by investigating the relationship between period and length of string for a simple pendulum. 1. Homework...

I had a drive that every few minutes makes a buzzing sound. Here's what SMART is telling me. ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000b 071 071 016 Pre-fail Always - 61213753 2...

does ever sound wave have a positive and negative frequency?

how can you identify the type of gun by the sound it makes ? Like if you had a recording of a gun shot but you Can't see the gun and you can find the bullet.

Homework Statement The longitudinal displacement of a mass element in a medium as a sound wave passes through it is given by s = sm cos (kx – ωt). Consider a sound wave of frequency 330 Hz and wavelength 0.95 m. If sm= 16 µm, what is the displacement of an element of air located at x = 1.1 m...

1) How good our approximations of thinking about waves as a function like sin? 2) The power of a sound wave, I have looked on the internet for derivations and all of them used calculus which is a quite expected thing so I skipped it because I still didnt take integration. However I found a proof...

While studying the difference between sound and light, I am puzzled by the following statement in this blog: Is this just another way of saying it doesn't need any medium? The Transmission medium Wikipedia page makes me think the vacuum of space is its "medium".

Let's assume a speed of sound of approximately 740 mph at sea level. If I there are two aircraft traveling in formation 1 mile apart (one in front of the other) at 730 miles per hour, how long will it take for the sound of single gunshot fired from the trailing aircraft to reach the lead...

What(if anything) is sound made of?

I'm doing a physics experiment for school, for which I am measuring the reverb time for specific frequencies in a room. What I did was record a 1000 Hz sound, and some time after it, and looked at its FFT on Audacity to see the intensity of just 1000 Hz at a given time. Manually, I can do this...

Hey guys, is it possible to replicate the sounds produced by exhaust gases in a car by using only hot air? Thanks in advance for your responses.

Homework Statement Moving through air, a wave hits a steady area of water with a angle of 13°. The velocity of the wave in air is 550 m/s and in the water 1650 m/s. What is the refraction angle of the wave? Does the angle move away or to the line of symmetry? Btw. I think I translated it...

i'm doing an experiment to study the effect of sound waves on fire and smoke and would like to know how can i produce sound waves with frequencies varying from 0-200 hz

Why does sound always move at the local speed of sound in a medium (in other words, why is there a set speed of sound for certain medium)? I understand that sound is a compression wave, but shouldn't a louder sound (i.e. one with a higher amplitude) move faster? What about a higher pitch noise...

Homework Statement Alas, after a sybaritic festival, the cheap upright piano in your fraternity house is found upright at the bottom of the house swimming pool. You decide to play Handel's Water music but first test the sound of middle C (261.6 HZ). The speed of sound in water is...

So I have working code of a : FFT Digital low pass and high pass filter and sound generator What cool projects can I make which these ?

Hello everyone, I am interested in analyzing sounds (both spectral plots and time plot). What type of hardware would I need? There are a lot of free softwares online... Are there educational hardware tools that are not too expensive? thanks!

Homework Statement A sound wave with intensity 2x10^(-3) W/m^2 is perceived to be modestly loud. Your eardrum is 6.0 mm in diameter. How much energy will be transferred to your eardrum while listening to this sound for 1.0 min? Homework Equations P=IA=(intensity)(area) =2x10^(-3) * (pi...

Is there a good description or formula regarding how the sound pressure from a constant source depends upon ambient pressure? That is, if I were to conduct an experiment where I put a source and a microphone in a container, and then change the pressure in that container with a pump, assuming...

Hi All, I am having trouble with my sound ( no output) and, after trying all the obvious things and more, I am trying to see if the registry settings (which contain initialization info for devices, among other things). Does anyone know how to check these settings for sound devices? Thanks.

Homework Statement Two speakers A and B are 3.50m apart and each one is emitting a frequency of 444Hz. However because of signal delays, speaker A is 1/4 of a period ahead of B. Find all points relative to the centerline between A and B where there is constructive interference. Include angles...

The other day I was at a river listening to some rapids. The sound produced by the rapids appeared to vary in pitch depending on how high up I was (squatting down to the ground and standing up produced about a fifth in the variation of the pitch); and I can't think why it should be? Many Thanks

Hello. This is my first post so I apologise if I've put it in the wrong category or done something wrong. Today in my physics lesson I was given a question where we were supposed to find the depth of a well, and we were given the suvat equations. The question was as follows: "A stone is...

I understand in a bulb when electrons flow they cause resistance and this heats up the bulb and the gases inside are ionised and they in turn emit light because their atoms become charged. How does flow of electrons cause sound? I know its an advanced explanation but what is the flow actually...

Two identical tuning forks vibrate at 256 Hz. One of them is then loaded with a drop of wax, after which 6 beats/s are heard. The period of the loaded tuning fork is? So, as the uploaded pictures shows, I did solve the problem, but I'm not sure why the f1 frequency is bigger than f2. I mean how...

Homework Statement Will the velocity of sound change if the source moves? Homework Equations The velocity of velocity of sound in air equals: $$V=\sqrt{\frac{\gamma RT}{M}}=const$$The Attempt at a Solution I think it doesn't change. But it seems to conflict with the equation ...

Homework Statement For school, I have to make a task about sound intensity and the distance to the sound source. I have to prove that the relation between these two is known as the inverse square law _1/ I_2 = ( _2/_1 )². Does someone know how I can plot the inverse square law or prove that it...

Introduction to environmental engineering 1. Homework Statement A sound level reading of 132 dB was taken near a construction site where some chippers were being used. When only one chipper was working, the sound level reading was 122 dB. Assume that all the chippers are located at the same...

Homework Statement Refer to the photos, question 21 and 22(the one with a helicopter) Homework Equations Both answers are A The Attempt at a Solution for question 21, if the counts to ten, there are 9 intervals. I divide 20 by 9 and divide it again by 2 and get 1.1s not 0.5s. for question 22...

Horsehair is a string of tiny bead-shaped growths -- from what I have read. Even that slides over strings until rosin allows the "beads" to grab temporarily. But if one bead pulls and releases the string, wouldn't the other strings in the horsehair "hank" dampen that sound? It obviously doesn't...

In physics, wave mechanics and vibration specifically, do the terms note, tone and mode mean the same thing or do they refer to difference things? Also what does the mode of oscillation exactly mean?

They certainly do sound periodic from observation. But is there a particular formula that proves that sound from Newton's Cradle is periodic?

Hey I am a layperson, and have very little understanding of physics. I'm trying to understand the relation between a magnetic field and air and how they are similar or dissimilar in terms of disturbance in them. Let me lay out the context from which I came to think about the question...

Hi everyone, I am looking to improve the transmission of sound from a small 1/2" electro-mechanical transducer through a plastic medium (about 1/4" thick). I understand plastic is not a great medium for this but I do not have the ability to change this. The defacto setup doesn't work too...

I've been trying to make a Sondhauss tube lately. My setup is a 17-cm long Pyrex test tube with a small piece of steel wool as the stack. I've been holding the closed end over a gas stove on full heat with a pipe wrench, but absolutely no sound is produced. What I am doing seems to be no...

Hi, I have a general question I was thinking about... So, in a liquid the particles are already very close together and as a result they are, in effect, not compressible. That being said, if we take water, for example, it is possible to compress is slightly. It requires, however, a great deal...