What is the formula for measuring sound?
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
703678
Two techniques: analog and digital.\nAnalog: the sound is a variation of air pressure.  This variation is "measured" by a microphone (or similar), to convert the pressure differences into variations of voltage.\nThis voltage variation is then used, after amplification, to act upon a "stylus" (in the case of Edison) that "vibrate" on a cylinder of soft wax, animated by a rotation and a horizontal translation.  The variations of the stylus can be read afterwards by retarting the process, this time fromt the stylus to a speaker.\nLater, the voltage variations where converted in magnetic variations that were "written" to a wire first, then to a tape (tape recorders).\nNowadays, the same voltage variations are "sliced" and measured many times per second, converted in numeric value, and it is the number that is recorded on some disc or solid state memory: this is the digital recording.
752071
L+ e = C/4N\n\nL is the resonance length.\n\ne is the end correction \n\nC is the speed of sound in air\n\nN is the frequency of the fork.\n\nThe above equation can be written as \n\n4NL + 4Ne = C.\n\n\nFor first fork, 4N = 1024.\n\n\n1024 x 0.32 + 1024 e = C --------------- (1)\n\nFor the next fork, 4N = 1536\n\n1536 x 0.208 + 1536 e = C----------------- (2).\n\nEquating (2) and (1) \n\n1536 x 0.208 + 1536 e = 1024 x 0.32 + 1024 e \n\n512 e = 327.68 - 319.49 = 8.19 \n\ne = 0.016 m = 1.6 cm.
589422
For a column of vibrating air with one closed end and one open end the equation is:\n\nlambda = 4L\n\nWhere L is the length of the tube and lambda is the wavelength of the standing sound wave.  Given the fact you know the frequency, and the speeed of sound, I think you can figure out the rest.
966327
I agree; c) is the right choice.  The other units are used to measure:\n\na)  power ratio\nb)  pressure\nd)  pressure (again)
577560
http://en.wikipedia.org/wiki/Sound_waves
906307
From wikipedia:\n\nFor sound intensity, I0 is typically chosen to be 10^−12 W/m2, which is roughly the threshold of hearing. When this choice is made, the units are said to be "dB SIL". For sound power, P0 is typically chosen to be 10^−12 W, and the units are then "dB SWL".\n\nThe value of 56.0 db is derived from the formula\n\ndb = 10*log(I/I0)\n\nFor 56 db, I/I0 = 10^5.6  From the above reference,  I0 = 10^-12 W/m^2;  Therefore I = 10^5.6*10^-12 = 10^-6.4 W/m^2\n\nSince the distance from the source was given in your problem, perhaps it meant "power level" rather than "intensity level".  If that is the case, you would figure the power using the formula\ndb = 10*log(P/P0), just as above, except that P0 is 10^-12 watts.  To get intensity at point A, divide by the spherical area at that point A = 4πr^2, where r = 3.8m
1067825
Decibels is a logarithmic scale, like the Richter scale for earthquakes and the luminous magnitude scale for star brightness.   Zero is the faintest sound most people can hear, which is assumed to be 10^ -16 watts per square metre of sound .   10 dB is 10x 10 times this level, which is 10^ -14 watts/sq.m.   65 dB, about the level of a conversation in a restaurant, is 10x 10^6.5 times the threshold level of 10^ -16 which works out at 3.16x 10^-10 watts/ square metre. 120 dB is about the level of a pneumatic drill, or 10 metres behind a jet aircraft on its takeoff run, or a couple of metres from the loudspeaker at an outdoor rock concert.It is 10 times 1 000 000 000 000 times the threshold level, or 0.001 watts / sq.m. of sound.   So every time you multiply the sound power by 10 you go up 10 dB.   150dB is reckoned to permanently and immediately deafen you.   Absolute silence is minus infinity dB because the logarithm of zero is minus infinity.
1080952
mass, volume and temperature.
300281
Sound travels through the air at about 330 meters/second.  Kids have been taught for years in Scouts that it takes 5 seconds for a the sound of a lightning-generated thunderclap to travel a mile.  It doesn't take very sophisticated electronics to generate a sound pulse, simultaneously start a clock, and measure the time it takes for the sound to bounce off its target and return.  Real estate agents for years have used a small device that does this to measure room sizes.  Limiting factors are the distance to be measured and the amount of sound reflected.
10297
The Decibel is a logarithmic measure of sound intensity and cannot usually be added as simply as adding apples to a basket.  Also, different sound sources interact with each other much as the ripples on a mill pond when you throw in one or more stones.  At one point the ripples add and at another they cancel each other where a crest meets a trough.  Crests add and troughs add negatively.  Then did you us a large and small stone?  I think you get the picture.  It is complex.\n\nThe sound level in Decibels is the sound energy being emitted by a device and can be measured in a special lab with a meter.  That is different from the sound energy received by the ear (which depends on many things including distance from the source(s) and reflection of the source(s) from walls, etc.).\n\nI was told that the net effect of two sound sources was not purely additive but more like considering each source to be a side of a square or rectangle then calculating the diagonal of the figure (hypotenuse by trig where A2 = B2 + C2 and 2 means squared).  Three sources would thus add as the diagonal of a cube, etc.
149054
In air, higher temperatures result in faster sound waves.  The formula is \n\nV = Vo SQRT( 1 + T/273) , where V = speed of sound in the air, T = temperature in degrees Celsius, and Vo= speed of sound at 0 degrees Celsius = 331 m/s.
782952
20Hz- 20kHz (audible frequencies)\n< 20Hz (infrasonic)\n> 20kHz (ultrasonic)\n\nlongitudinal wave - sound wave\nthe rest are transverse waves
801431
Go to the Control Panel and look for Sounds, Speech, and Audio devices. You can check them there.
143776
hey now.  just a minute.  density is not the only factor that determines the speed of sound in a solid.  also at issue is the "stiffness" of the material; in physics terms this is called the elastic modulus.  so the speed of sound is higher in diamond (12000 m/s) than it is in lead (1600 m/s) even though lead is denser.\n\nin general the equation for the speed of sound in a bulk material is v = sqrt(B/p) where B is the elastic modulus and p is the density.  \n\nthe elastic modulus is not a particularly simple quantity to derive from first principles, compared to density - it has to do with how the material is structured on an atomic level.  however the speed is certainly easy to measure.  here is a page with some tabulated values for various materials:  http://hyperphysics.phy-astr.gsu.edu/hbase/tables/soundv.html\n\nit shows that brass has a higher speed of sound.
768083
depends how much the volume is off by
1166160
give me a minute to grab my decibel meter and tie it to Bessie's butt......\n\ncome on ....\n\ncome on .... \n\nrip one girl....\n\nBRTHFFFFFFDFD\n\nalright now let's see\n\nWow 78db spl at 6 inches. With that information you can calculate acoustical power.