Sound Definition and 1000 Threads

sound created by blowing across the top of the bottle produces sound due to standing waves created on air inside the bottle. why blowing inside the bottle does not produce sound but only across? how vibrations created on air inside the bottle propagate in space as they are separated from...

when you slide your thinger around the rim of glass it produces resonance the matter which vibrates is a glass, not air, right? i understand that when ou hit a glass once it produces sound as by hitting you displace mass of glass from its equilibrium. but why sliding the rim produces sound...

The symbol, c, represents both the speed of light and the speed of sound in most scientific reference texts. Can the speed of sound be substituted for the speed of light in the Michelson-Morley (MM) formula: T = [L / (c - v)] + [L / (c + v)]? Consider an observer on a train of length, L. It...

As we all know, we are always surrounded by a "sea" of sound(Of cars,air,farts etc :wink:. Lol) How can our voice be transmitted by the air without getting disturbed by other sounds? Sound is a longitudinal wave. So imagine another wave traveling perpendicular to our wave. Then at the point...

Homework Statement I am writing a mathematics paper and I would like to know how do you mathematically say "put on the other side" of the integral, I have a constant in the integral and I want to say that I'm putting it on the other side. I attached a picture where I show with a arrow...

Is it possible to use the way sound reflects off an object to determine it's density?

Homework Statement "A continuous sound wave with a sound intensity level of 80dB passes through a hole in a wall which has a cross-sectional area of 3m^2. How much energy passes through this hole in 10 minutes, in joules?" If anyone can show me how this problem is solved it's be much...

Is it to identify something (not necessarily very accurately but at all) with sound? Also, i know its possible with light but i don't exactly understand how, can someone explain?

Homework Statement A tuned violin, with strings of 31.6 cm each, is placed in front of a speaker. When varying the speakers frequency between 500 and 1500 Hz, it was discovered that a certain string only vibrated at 880 Hz and 1320 Hz. Determine the velocity of the wave in this string...

Homework Statement Speakers L_1 and L_2 are placed at a 2 m distance from each other. The speakers send out soundwaves that are in the same phase and the loudness (?) is examined in the point P (see figure). The velocity of the sound is 343 m/s and the distance L_2P is 6 m. L_1 L_2...

A test question I was asked earlier in the year has been hanging around in the back of my mind: "If a radio is moved 3x further away from you, how is its loudness affected?" To answer this question one needs to know what determines the loudness of sound. What determines the loudness of...

Homework Statement for part a , since we know that the sand particles will vibrate will max amplitude at antinode and the displacement of partcles is 0 at node. then , the sand should heap at antinode . why the solution gives the sand heap at nodes? Homework Equations The Attempt...

Homework Statement i have attached the notes from 2 books below, i know that the graph of pressure of sound waves lag behind the displacement grpah by 90 degree. so it should be p=p max sin (wt-kx-(pi/2)) am i right? why the another book gives p=p max sin (wt-kx+(pi/2)) ? which is correct...

I was suddenly asked this question by a friend... How a 'cats & dogs' rain would affect the velocity of sound through air?(as we know velocity of sound through water is five times than in air) I just couldn't be sure how to answer it... The raindrops are really small but there's a lot of...

Hello! If a person hear song continuously for 15 hours every day for one year by head-phone then will there be any effect on his/her brain?

You are in a park when you spot your friend 100 m away. At what lowest decibel should you shout your greetings so that your friend can just hear you? Assume that your friend has normal hearing. My prof never gave an example of how to do this and I can't figure it out. The correct answer is...

“A tractor beam reels in objects with sound” “A newly constructed device generates a beam of concentrated sound that, for the first time, exerts a continuous, perceptible tug on objects large enough to see.” https://www.sciencenews.org/article/tractor-beam-reels-objects-sound

Hi, I am posting here as I can't get a satisfactory answer from google. Could anyone explain to me why low frequency sounds diffract better than high frequnecy sounds around a corner (eg the wall of a building). I understand the idea of 'wave diffracts more when opening is around the same...

Homework Statement A steel cable is vibrating in its third harmonic. The Frequency is 150Hz 1. What is the length of the cable? 2. What is the wavelength?Homework Equations The Attempt at a Solution I am really stuck

I need help with these problems. 1. Speed of Sound in Air. Two seconds after firing a rifle at a target, the shooter hears the impact of the bullet. Sound travels at 1100 feet per second and the bullet at 1865 feet per second. Determine the distance to the target (to the nearest foot). 2...

Is there a way to convert light energy to a sound energy? I read an article and the URL is http://www.photonics.com/Article.aspx?AID=52646 It is described that nano material lenses are used. Is there a much simpler way that I convert light to sound?

Homework Statement A loudspeaker emits sound isotropically with a power of 100db. Find the intensity in w/m at a distance of 20 from the source Homework Equations Intensity=power/area, For sound wave... power=ro*a*2pi^2*f^2*v*A^2, and I=2pi^2*ro*f^2*v*A^2. db=10log_10_(I/I_0_)...

So today I was holding up an umbrella near someone playing music, and it sounded like the music was coming from the top of my umbrella. Is this a similar effect to a radio? Can it be seen as sound being a disturbance of the air that causes the metal to vibrate which amplifies it to make it...

Homework Statement Two loudspeakers are placed beside each other and produce sound of the same intensity at the position of a listener. One speaker produces a low note of 40 Hz and the other produces a high note of 2560 Hz. What is the ratio of the maximum displacements of the speakers...

Homework Statement In the figure below, two speakers S1 and S2 emit sound waves of wavelength 2m, in phase with each other. Let Ap be the amplitude of the resulting wave at point P, and Aq be he amplitude of the resultant wave at point Q. How does Ap compare to Aq? a. Ap<Aq b. Ap=Aq c...

I am learning sound. My teachers and textbook say loudness of sound is a subjective quantity, it is different for every person, while intensity is the objective quantity. The first section says intensity is a measurable quantity, WHILE LOUDNESS IS JUST A SENSATION. On the very next page they...

This is not homework but rather a concept question. If there was a siren on the front of an airplane that is traveling greater than the speed of sound, would there still be a sound emitted? If the airplane was traveling toward me what would be the frequency? Would I heart it? Where...

Homework Statement Two trains A and B are moving with speed 20m/s and 30m/s respectively in the same direction on the same straight track with B ahead of A. The engines are at the front ends. The engine of trains A blows a long whistle. Assume that the speed of sound of whistle is...

1. A sound wave with frequency f = 2300Hz is sent into a circular tube of radius R=160cm through an opening at some point A. A receiver lies at point B, separated from A by an angle α=130°. The speed of sound in air is v=330 m/s. Sound propagates from A to B in both directions along the...

So, sound is a longitudinal wave, while light is a transverse wave. The speed of sound varies going from one medium to another directly proportional to the bulk modulus and inversely proportional to the density of the new medium (i.e. from air to a steel pipe). Let's say a sound wave (consisting...

Anybody has reference paper on light and sound wave's theoretical analogies? I want to read about the analogies and difference between this interactions in terms of waves. Thank you in advance. AGZ

Is there any way to focus a sound wave BEHIND an acoustic lens i.e. the source and receiver are on different sides of the lens? Will it result in a significant loss of sound energy?

Hi guys and girls, Just had a question I have been thinking about for a while. Suppose you have a sound maker than makes a pure tone at a particular frequency. You play this tone for an instant directed directly at a flat wall (not absorbent at all). If you could measure the reflected tone...

My tenth grade physics textbook says that sound travels faster in solids than air. But it also says sound will travel faster in air if its density decreases. I didn't really get the logic, as solids are denser than air, and that is why sound travels faster. Then they say as temperature of air...

Homework Statement The sound pressure level is 80db at a distance of 30 meters. What is the dBSPL at 60 meters? Homework Equations My book has provided me the following formula: dBSPL = dBr-20log(di/dr) - but it has not explained what "di" and "dr" are.The Attempt at a Solution I've been...

Okay, so I was listening to someone via tinychat explaining how our current understanding of sound was wrong in some sense. He claimed that the source of the propagation of sound waves HAD to be moving faster than the speed of sound (in air). One particular analogy he used in order to...

Why is sound louder in a room with many people? Thanks

like for example digital unit measurement for clear images in devices is ...pixel

Can we focus parallel sound waves using convex and concave lenses since they essentially follow the same laws of refraction as light? If not, is there any way to focus parallel beams of sound to converge at a point?

Hi all, First, I hope this is in the right place, apologies if it isn't. I'm looking into the possibility of deriving sound from the simulated actions of simple bodies in a 3D space. As a toy example of my aim, I hope to be able to compute the sound that would be generated by a metal...

Not a homework... simple curiosity by trying to know this a bit better in order to learn and understand possible effects of sound to marine mammals auditory systems. In sea water, at distance of 1m from a localized sound source, you measure the intensity level as 237 dB. How far away from the...

Homework Statement A source of sound S and a detector D are placed at some distance from one another. A big cradboard is placed near the detector and perpendicular to line SD as shown in figure. It is gradually moved away and it is found that the intensity changes from a maximum to a minimum as...

Can someone please help explain an experiment which I am struggling to understand. You have a speaker without any of the outer casing (just the small disk part) and secure it onto a clamp stand. You then have two microphones; one above the speaker and one below it which are both the same...

Hello I am trying to get into physics and astronomy as a hobby so please excuse the crudity of my posts, I regrettably have no physics education past high school level but nevertheless I aim to slowly but surely learn either self-taught or through some further eduction whether at college or...

Hi, Suppose the police car moves faster than sound's speed and runs away from the person on the street. Will the person hear the siren? Regards,

Hi, Suppose the police car moves faster than sound's speed and runs away from the person on the street. Will the person hear the siren? Regards,

I cannot understand the following: Imagine you have 2 sound sources and build up an interference experiment, where far away from the sources you have a receptor. Imagine you put the receptor at the same distance from the sources. If you turn off one source the receptor will receive a sound...

Which one has the more dangerous health effect...ultrasound or infrasound.? and why...

Which one has more dangerous effect for health ...ultrasound or infrasound.? and why...

FYI, I'm not very knowledgeable in this topic however I have noticed something intriguing whenever dealing with sound levels and feedback. My question is.. Why is it that if I were to say turn my headphones to 100% volume and my PC volume is 50% the sound will sound a little "distorted or fuzzy"...