does anybody know the velocity of a sound wave thru helium?! i need it for a physics question?
971254
v=sqrt(k*P/rho), where k is Adiabatic index, rho is density of helium\nfor monoatomic gases k=(3+2)/3=1.667\nrho=0.1786 g/L=0.1786kg/m^3 under standard conditions\nP=1atm=98 066 Pa\nso v=956.7m/s\n\nbut it's 970m/s from http://www.teachersparadise.com/ency/en/wikipedia/h/he/helium.html
15926
.6 m/s.  and here's why:\nthe distance between two crests is the wavelength, and the "one wave goes by every 5 sec" is it's period.  The formula is v=fw where w(which is normally lambda, but i cant put greek letters on here) is wavelength, f is frequency, and v is velocity. you don't have frequency, but f=1/T where T is the period, so f would just be 1/5.  So then you go back to the first formula and multiply 3x(1/5) and you get 3/5 which is .6 m/s.\n\nAnd FYI, this formula does NOT include index if refraction and therefore it doesn't matter what medium the wave is traveling through.  Yes, velocity get's slower with a more dense medium, but the different medium would also make the frequency and period change, so therefore, the period you were given corresponds to whatever medium the wave is in.  There can only be one wave speed for that period/frequency with that wavelenth.  I mean, the 1/5 that we got for frequency means that 1/5 of a wave passes per second.  Now if each wave is 3 meters long, that means that we have to find 1/5 of 3 meters to fnd out how many meters of this particular wave passes per second.  1/5 of 3m (or 1/5 x 3) is 3/5(which is the answer, .6)  Meaning that the wave is passing by at a speed of 3/5(.6) meters per second.  I hope this helped you to understand the concept behind that formula :)
1097080
a)\n\n(change in frequency)/(recorded frequency) = (Speed of emitter)/(wave speed).\n\nChange in frequency = 22 Hz\nRecorded frequency = 820 Hz\nSpeed of emitter = what you are trying to find.\nWave speed = speed of sound = 340 m/s\n\n(22 / 820) x 340 = 9.12 m/s\n\nb)\n\nThe frequency of the echo is (I'm guessing for this one sorry) double the regular frequency, which is 1684 Hz.\n\nc) \n\nThe frequency heard by the man is 820 Hz by definition isn't it? Thats the frequency as the boy passes anyway.\n\n[EDIT] Wait I just realised your whole question makes no sense. Due to the limited info in the question I was assuming you meant it falls to 820 Hz from the emission frequency at the point where the boy passes the man. But why would the frequency fall? The point where the boy passes the man is the point where the frequency experienced by the man is highest.\n\nOh well I hope my answer helped a bit anyway.
792662
Frequency = velocity of propagation / wavelength.\n\nFor light, we assume it is moving in a vacuum, so vp is 3e8 m/s.  The wavelength of 310nm is 310e-9 meters.  Then we plug the numbers in, and we get (3e8 m/s) / (310e-9 m) = 967.742e12 Hz because 1/s is the same as cycles/sec, which is a Hertz.
67284
well the formula is the square root of 3kT/m  where k is the boltzman constant(1.38066 x 10^-23 J/K) T is in Kelvin so you would have to convert(just add 273 to the temp in Celcius) so your T is 290K and m is the mass. the mass can be found using the density of water(1000 kg/m3) the formula for density is d=m/V and V can be found by using the volume of a sphere, 4/3(pi)r^3 oh, and don't forget to convert the nanometers into meters, then cut the diameter in half for radius.\nusing this information to get you started, you should be able to do it yourself. so you should try it first before reading further :) im sure you were familiar with all of those formulas, you just need to remember to think of things all at once so you can put them together.\n\nok, so we start with the rms velocity formula. first problem is that we need mass. ok, lets solve for mass using density. oh right, we need volume, ok, lets solve for volume then:\nwe need to make the diameter into meters, so thats 1.0 x 10^-8 meters. now we cut this in half to get the radius(r) so that's 5.0 x 10^-9.\nV=(4/3)(pi)r^3\nV=(4/3)(3.14159)(5 x 10^-9)^3\nV=5.236 x 10^-25 m^3\nnow we have volume, so using the density of water(1000 kg/m3), we can solve for mass:\nd=m/V\n1000=m/(5.236 x 10^-25)\nm=5.236 x 10^-22 kg\nok, now we have mass, so we can use our original rms velocity formula and solve for velocity. *sigh* finally.\n\nv(rms)= sqrt[3kT/m]\nv(rms)= sqrt[3(1.38066 x 10^-23)(290)/(5.236 x 10^-22)]\nv(rms)= 22.94 m/s\n\ni would check my math if i were you though, i tend to make stupid calculator errors. the concepts are there though :p
1093017
Your question is incomplete, part of it looks to be cut off.\n\nThis is just a guess, but the question almost seems like it is asking how long after the student claps his hands does he hear the eco bounce back off the wall.\nIn this case, one would need to know the speed of sound (or one could just estimate it to be about 340.29 m/s).\nSince speed is given as distance traveled per unit time, one can calculate the amount of time it would take something traveling at a given speed to be the distance traveled divided by the speed.  In this case with the sound, the sound traveled to the wall (165 meters) and back again (another 165 meters), for a total distance of 330 meters.
515643
The 'speed of sound (from Latin celeritas, "velocity") varies depending on the medium through which the sound waves pass. It is usually quoted in describing properties of substances (e.g. see the article on sodium). In conventional use and in scientific literature sound velocity v is the same as sound speed c. Sound velocity c or velocity of sound should not be confused with sound particle velocity v, which is the velocity of the individual particles. More commonly the term refers to the speed of sound in air. The speed varies depending on atmospheric conditions; the most important factor is the temperature. The humidity has very little effect on the speed of sound, while the air pressure has an effect (see equations later in the page). Sound travels slower with an increased altitude (elevation if you are on solid earth), primarily as a result of temperature and humidity changes.
302886
When sound travels through a denser material, it's velocity decreases. So say I am sitting in the living room with the FBI director discussing top secret documents, my voice reaches the wall, and then the velocity of sound decreases inside the wall. Now you, being a spy are listening intently on the other side of the wall. When the sound wave reaches you it has lost some of its energy. That is loose talk though, more like it has lost it's intensity because it had a much denser medium to travel through, namely the wall. Now when you put the wine glass to your ear, you are ensuring that the waves that come through the wine glass to your ear are not going anywhere outside your glass, because although the amplitude of the wave is restricted, the wave is contained in a closed space due to reflection of the wave off of the sides of the glass. But that is another loose non physicsy explanation. The real deal has to do with the resonance of the wave inside the glass and the formation of node or antinode when the wave reaches your ear. But that does involve gruesome calculations and the formulae tend to slip your mind. But for the purpose of everyday life, the previous explanation is quite sufficient.. Hopefully you agree with me..eh?\n\nAyerhs.
160215
The speed of sound is defined (thermodynamically) as:\nc^2= dp/d(rho), \nwhere c is the speed of sound, p is pressure, and rho is density.\n\nFor a solid material, c^2=E/rho, where E is Youngs modulus.  So material with a low density and high modulus would have the fastest speed of sound.  Carbon nanotubes come to mind as filling those requirements.
409027
Speed of sound is dependent on temperature. Speed of sound is directly proportional to the square root of pressure and inversely proportional to the square root of the density of the medium.\nv is proportional to P(pressure) and inversely proportional to D(density)\nP/D=RT/M    where R is the gas constant, T is the absolute temperature and M is the molecular mass.\n\nTherefore, Pressure is directly proportional to the absolute temperature of the gas.\nHence,\nv is directly proportional to the temperature.
789953
Measure the speed of sound by help of an echo, a stopwatch and a tape-measure. (depending on temperature it is about 430 m/s.\nRepeat your measurements at least 10x and have the average.\nGood luck\n\nTh
680357
sound travels the fastest in solids.slower in liquids and slowest in gases.\nso the answers to tour question is it travels faster in ice\nthe volume has nothing to do with the speed of sound.it is only the physical form,solid,liquid or gas
1142877
B through fresh air.  But blow your teacher's mind and ask them what media it is passing through.  After all, since sound is a wave function it is dependent upon the media it passes through.  For example, sound would find it difficult to pass through 3 feet of concrete.
474712
At normal atmospheric pressure, the temperature dependence of the speed of a sound wave through air is approximated by the following equation:\n\nv = 331 m/s + (0.6 m/s/C)*T\nwhere T is the temperature of the air in degrees Celsius. Using this equation is used to determine the speed of a sound wave in air at a temperature of 20 degrees Celsius yields the following solution.\n\nv = 331 m/s + (0.6 m/s/C)*T \nv = 331 m/s + (0.6 m/s/C)*20 C\n\nv = 331 m/s + 12 m/s\n\nv = 343 m
835410
You need to get your units in a consistent form.  I suggest changing the velocity of the electron to 2.5E6 m/s so when you divide it into c-----------WAIT A MINUTE!-----Yor formula is NOT right, because you're dividing a speed by a speed, which will give a dimensionless answer.  Wavelength is a LENGTH, so the answer must come out that way.  I forget the formula you're refering to, but what you've typed isn't it................
181822
Sound travels in a wave.  Actually travels best through a solid.
1121807
Sound travel in air with a speed of 331.4 m/s. For sound to travel from the student to the wall and back it must travel 165*2=330 m.  For sound to travel 330 m , it will take approximately 330/331.4=..9958s.