Saturday

June 25, 2016
Number of results: 85,940

**physics**

Expensive amplifier A is rated at 250 W, while the more modest amplifier B is rated at 45 W. (a) Estimate the sound level in decibels you would expect at a point 3.5 m from a loudspeaker connected in turn to each amp. (b) Will the expensive amp sound twice as loud as the ...
*November 7, 2013 by emy*

**physics**

Expensive amplifier A is rated at 210W , while the more modest amplifier B is rated at 45W . Estimate the sound level in decibels you would expect at a point 9.0m from a loudspeaker connected in turn to each amp.
*November 18, 2013 by waves*

**LOGS**

The decibel level of a sound is given by dB=10log(EE0), where E0=10−12wattsm2 and E is the intensity of the sound. (a) Find the intensity of a 80-decibel sound. E= watts per square meter. (b) How many times more intense is the sound from (a) than a 50-decibel sound? A ...
*February 21, 2016 by Sarah*

**physics**

Factory Worker A is exposed to a sound of a constant intensity of 6.30 × 10–4 W m–2 at a distance of 1.00 m from a noisy machine. The frequency of the sound is 4.00 kHz. (a) What is the sound level in decibels (dB) of this sound? (b) By what factor would the amplitude of this ...
*June 12, 2011 by nancy*

**Algebra**

The Occupational Safety and health Administration (OSHA) estblished permissible sound exposures in the work-place. This is modeled by the equation: S=-2.817H + 108.9 Use the formula for the problem: S=maximun permissible sound level in decibels H=number of hours of exposure ...
*February 8, 2008 by G*

**Algebra**

The Occupational Safety and health Administration (OSHA) estblished permissible sound exposures in the work-place. This is modeled by the equation: S=-2.817H + 108.9 Use the formula for the problem: S=maximun permissible sound level in decibels H=number of hours of exposure ...
*February 8, 2008 by G*

**physical sciences**

a thunderclap 200m away delivers 3.75E^-5 W/m^2 of sound. What is the sound level in decibels? What is the intensity of the sound at 10m from the thunderclap? What is the sound level in decibels 10m from the thunderclap?
*October 21, 2008 by Valerie*

**Physics**

The intensity due to a number of indipendent sound sources is the sum of the individual intensities. A) When four quadruplets cry simultaneously, how many decibels greater is the sound intensity level than when a single one cries? B) To increase the sound intensity level again...
*March 29, 2008 by Amanda*

**PreCalculas**

The psychological sensation of loudness B is measured in decibels and is defined with reference to the intensity, , of a barely audible sound by the following equation. In this equation, I is the intensity of the sound in question. B=10log 1/1o If the sound of a jet engine ...
*November 30, 2015 by Ryan*

**Math**

Formula given: The decibel (dB) scale for measuring loudness, d, is given by the formula d = 10 log base ten(I X 12 to the power of 12) where I is the intensity of sound in watts per square metre. a) Find the number of decibels of sound produced by a jet engine at a distance ...
*February 16, 2014 by Donna*

**Algebra 2**

Can someone help me? I'm really confused. The loudness L of a sound in decibels is given by L= 10log(base10)R, where R is the sound's relative intensity. If the intensity of a certain sound is tripled, by how many decibels does the sound increase?
*March 1, 2010 by Ana*

**physics sound**

1. A stone is dropped from rest into a well. The sound of the splash is heard exactly 1.50 s later. Find the depth of the well if the air temperature is 10.0°C. 2. Calculate the sound level in decibels of a sound wave that has an intensity of 2.25 µW/m2
*April 17, 2008 by Chris Adison*

**algebra 2**

the loudness L of a sound in decibels is given L=10log10R, where R is the sound's relative intensity. if the intensity of a certain sound is tripled, by how many decibels does the sound increase? due tomorrow, tuesday, april 5th, 2011. help pleaseeeee ;)
*April 4, 2011 by math challenged*

**Physics**

Point A is 5 m from a loudspeaker. At point B, the loudspeaker sounds half as loud as at point A. How far is point B from the loudspeaker? I get 50 m, but the answer is supposed to be 15.8 m. I need to know what I'm doing wrong. By my (apparently flawed) reasoning: Point A is ...
*February 10, 2010 by Reed*

**Grade 12 Math Please help!!**

Please can anyone answer this which I have posted previously? Anyone with knowledge of this area of maths? Thanks in anticipation. :) Formula given: The decibel (dB) scale for measuring loudness, d, is given by the formula d = 10 log base ten(I X 12 to the power of 12) where I...
*February 17, 2014 by Donna*

**Algebra II**

1. A sound has an intensity of 5.92 „e 1025W/m2.What is the loudness of the sound in decibels? Use . 2. Suppose you decrease the intensity of a sound by 45%. By how many decibels would the loudness be decreased?
*January 25, 2012 by Nick*

**phyiscs repost 2**

Calculate the sound level in decibels of a sound wave that has an intensity of 2.25 µW/m2 For this question don't I use B=log10(I/IO) So it would be B=log10(2.25/1.0e-12) right?
*April 19, 2008 by chris adison*

**physics**

A 14-Ω loudspeaker, a 9.0-Ω loudspeaker, and a 3.2-Ω loudspeaker are connected in parallel across the terminals of an amplifier. Determine the equivalent resistance of the three speakers, assuming that they all behave as resistors. Answer: (1/14)+(1/9)+(1/3.2...
*February 12, 2015 by Anonymous*

**physics**

1. A stone is dropped from rest into a well. The sound of the splash is heard exactly 1.50 s later. Find the depth of the well if the air temperature is 10.0°C. 2. Calculate the sound level in decibels of a sound wave that has an intensity of 2.25 µW/m2
*April 18, 2008 by Chris Adison*

**Physics**

Hi I am absolutely stumped on this question. A loudspeaker is placed between two observers who are 110 m apart, along the line connecting them. If one observer records a sound level of 60.1 dB and the other records a sound level of 74.9 dB, how far is the speaker from each ...
*November 28, 2008 by Joey*

**Physics**

Hi I am absolutely stumped on this question. A loudspeaker is placed between two observers who are 110 m apart, along the line connecting them. If one observer records a sound level of 60.1 dB and the other records a sound level of 74.9 dB, how far is the speaker from each ...
*November 28, 2008 by Joey*

**Physics**

Hi I am absolutely stumped on this question. A loudspeaker is placed between two observers who are 110 m apart, along the line connecting them. If one observer records a sound level of 60.1 dB and the other records a sound level of 74.9 dB, how far is the speaker from each ...
*November 28, 2008 by Joey*

**Physics**

Hi I am absolutely stumped on this question. A loudspeaker is placed between two observers who are 110 m apart, along the line connecting them. If one observer records a sound level of 60.1 dB and the other records a sound level of 74.9 dB, how far is the speaker from each ...
*November 28, 2008 by Joey*

**physics repost**

1. A stone is dropped from rest into a well. The sound of the splash is heard exactly 1.50 s later. Find the depth of the well if the air temperature is 10.0°C. 2. Calculate the sound level in decibels of a sound wave that has an intensity of 2.25 µW/m2
*April 19, 2008 by chris adison*

**physics repost**

Calculate the sound level in decibels of a sound wave that has an intensity of 2.25 µW/m2. F
*April 19, 2008 by chris adison*

**physics**

A loudspeaker is placed between two observers who are 114 m apart, along the line connecting them. If one observer records a sound level of 61.6 dB and the other records a sound level of 81.3 dB, how far is the speaker from each observer?
*December 2, 2008 by Anonymous*

**physics**

A loudspeaker is placed between two observers who are 111 m apart, along the line connecting them. If one observer records a sound level of 51.9 dB and the other records a sound level of 82.5 dB, how far is the speaker from each observer?
*November 30, 2010 by Linda*

**Physics**

If one machine creates a level of 90 decibels, what decibel level would be generated by 50 of these machines? If sounds are created at random, the net intensity is found by adding the individual intensities-not the decibels. Ignore distance effects.
*April 6, 2011 by Lindsey*

**Physics**

Two sounds have measured intensities of I1 = 100 W/m2 and I2 = 300 W/m2. By how many decibels is the level of sound 1 lower than that of sound 2?
*March 19, 2011 by Jane*

**Math**

On th decibel scale, the loudness of a sound, in decibels, is given by D=10log(I/I0), where I is the intensity of a sound barely audible to the human ear. If the intensity of a sound is 10^11I0, what is the loudness in decibels? (please note the I0 is supossed to be I lower 0.
*April 18, 2010 by Help!!*

**physics**

Two sounds have measured intensities of I1 = 102 W/m2 and I2 = 408.00 W/m2. By how many decibels is the level of sound 1 lower than that of sound 2? Answer in dB
*November 24, 2014 by May*

**Physics**

Two sounds have measured intensities of I1 = 110 W/m2 and I2 = 330.00 W/m2. By how many decibels is the level of sound 1 lower than that of sound 2? Answer in dB.
*December 1, 2014 by Hannah*

**physics**

NEED HELP WITH ONLY PART C Two 135.1.0-W speakers, A and B, are separated by a distance D = 3.6 m. The speakers emit in-phase sound waves at a frequency f = 11800.0 Hz. Point P1 is located at x1= 4.50 m and y1 = 0 m; point P2 is located at x2 = 4.50 m and y2 = –y. a) ...
*March 27, 2012 by sara*

**physics**

The loudest sound in Earth’s history is believed to be the explosion of the volcanic island of Krakatoa, back in 1883. Physicists estimate that the intensity of the sound produced was 1.0×107 W/m2. How many decibels does this correspond to?
*July 29, 2013 by neven*

**Physics HELP!!**

A loudspeaker is placed between two observers who are 113m apart, along the line connecting them. If one observer records a sound level of 51.8dB and the other records a sound level of 75.8dB, how far is the speaker from each observer? Enter the longest distance first.
*November 30, 2012 by Angie*

**physics**

A stereo speaker emits sound waves with a power output of 100W. (a) find the intensity 10.0m from the source. B) find the intensity level in decibels, at this distance. C) at what distance would you experience the sound at the threshold of pain,120dB?
*April 10, 2007 by sammy*

**physics**

The sound level in decibels is typically expressed as β = 10 log (I/I0), but since sound is a pressure wave, the sound level can be expressed in terms of a pressure difference. Intensity depends on the amplitude squared, so the expression is β = 20 log (P/P0), where ...
*November 16, 2011 by maria*

**physics**

The sound level in decibels is typically expressed as β = 10 log (I/I0), but since sound is a pressure wave, the sound level can be expressed in terms of a pressure difference. Intensity depends on the amplitude squared, so the expression is β = 20 log (P/P0), where ...
*November 16, 2011 by melisa*

**physics**

The sound level in decibels is typically expressed as β = 10 log (I/I0), but since sound is a pressure wave, the sound level can be expressed in terms of a pressure difference. Intensity depends on the amplitude squared, so the expression is β = 20 log (P/P0), where ...
*November 17, 2011 by maria*

**Reading Comp. **

The modern hearing aid is, essentially, a miniature public-address system, which converts sound into electrical energy and then converts it back to sound again. A hearing aid can increase the sound level by sixty decibels or more, but it also distorts the sound to some extent...
*March 28, 2011 by Arlynn*

**Physics**

I am reposting this since I did so incorrectly the first time. (I apologize for posting it twice the first time as well...I accidently hit refresh) Here is the problem with the proper units: You are trying to overhear a juicy conversation, but from your distance of 15.0m , it ...
*January 18, 2010 by Nicole*

**physics - sound level**

The source of a sound wave has a power of 2.50 µW. Assume it is a point source. (a) What is the intensity 6.70 m away? I used I = Power / 4*pi*r^2 and found I to be 4.43x10^-9 W/m^2 (b) What is the sound level at that distance? Sound level = 10 dB*log [(Intensity)/(Intensity ...
*April 21, 2007 by COFFEE*

**Physics**

While peforming a concert , Queen plays at average intensity levels of 2 W/m^2. Then during a sudden loud part of the music, the amplitude of the sound waves , initially A1 increases by a factor of 5. By how many decibels does the sound level increase?
*June 13, 2011 by Matt*

**physics**

An electronic point source emits sound isotropically at a frequency of 3000 Hz and a power of 34 watts. A small microphone has an area of 0.75 cm2 and is located 158 meters from the point source. a) What is the sound intensity at the microphone ? To find intensity i tried I=...
*April 21, 2010 by caleb*

**Algebra**

Find the number of decibels for the power of the sound. Round to nearest decibels. A rock concert, 5.21 x 10^-6watts/cm^2 D= dB
*November 3, 2012 by CLara*

**algebra **

A sound power level reading of 127 dB was taken near a construction site where chippers were being used. When all but one of the chippers stopped working, the sound power level reading was 120 dB. Estimate the number of chippers in operation when the reading of 127 was ...
*April 26, 2011 by Massiel*

**chemistry**

A sound power level reading of 127 dB was taken near a construction site where chippers were being used. When all but one of the chippers stopped working, the sound power level reading was 120 dB. Estimate the number of chippers in operation when the reading of 127 was ...
*April 26, 2011 by Massiel*

**Physics**

In a resonance-tube containing air, the source of sound is a small loudspeaker driven by a variable-frequency oscillator. The distance between successive antinodes is 10 cm for a frequency of 1625 Hz. When the frequency is slowly reduced, the standing wave pattern at first ...
*March 16, 2013 by Priscy*

**physics**

Jane and Sam alternately pound a railroad spike into a tie with their hammers. The crew chief has a migraine, and notes that Jane's hammer blows cause a sound with intensity 5.0 times greater than the sound that Sam makes when he swings his hammer. What is the difference in ...
*April 5, 2011 by shanelle james*

**Bio Help Please **

1)How can you indicate that the bacteria have taken up the plasmid? 2)What is the purpose of the LB/amp(-) plate? Should there be bacterial growth on the plate? 3) Why would one compare plates LB/amp (-) and LB/amp (+)?
*March 30, 2013 by Melissa*

**Bio Help Please!!!**

1)How can you indicate that the bacteria have taken up the plasmid? 2)What is the purpose of the LB/amp(-) plate? Should there be bacterial growth on the plate? 3) Why would one compare plates LB/amp (-) and LB/amp (+)?
*March 31, 2013 by Melissa*

**statistics**

Hearing levels or!@#$%^&pit noise in an aircraft can damage the hearing of pilots who are exposed to this hazard for many hours. Noise level is described as Low=under 88 decibels, Medium=88-91 decibels, High=92^decibels. At a = .05, is the!@#$%^&pit noise level independent of ...
*June 23, 2008 by Gayla*

**Physics**

A speaker at an open-air concert emits 600 of sound power, radiated equally in all directions. a)What is the intensity of the sound 7.00 from of the speaker? I =0.974 W/m^2 b) What sound intensity level would you experience there if you did not have any protection for your ...
*May 28, 2012 by JessicaP*

**Physics**

The distance between a loudspeaker and the left ear of a listener is 2.19 m. (a) Calculate the time required for sound to travel this distance taking the speed of sound to be 343 m/s. (b) Assuming that the sound frequency is 525 Hz, how many wavelengths of sound are contained ...
*March 3, 2013 by Tim*

**algebra**

The loudness, L L, of a sound (measured in decibels, dB) is inversely proportional to the square of the distance, d d, from the source of the sound. Round to 3 decimal places. A person 15 feet from a jetski, it is 75 decibels loud. How loud is the jetski when the person is 47 ...
*February 9, 2016 by sam*

**Logarithms**

Show that, if one sound is 10 decibels louder than a second sound, than the first sound is 10 times as intense as the second sound.
*March 28, 2012 by Anonymous*

**Physics**

At a recent rock concert, a dB meter registered 118 dB when placed 1.60 m in front of a loudspeaker on the stage. (a) What was the power output of the speaker, assuming a hemispherical radiation of the sound and neglecting absorption in the air? Answer in W (b) How far away ...
*April 1, 2011 by BILL*

**Grade 12 Advanced Functions Math**

Hello! Can someone please help me out for this question? The loudness, L, of a sound in decibels can be calculated using the formula L= 10 log(I/ F) where I is the intensity of the sound in watts per square metre and F= 10^ -12 . A singer is performing to a crowd. Determine ...
*January 19, 2010 by Joan*

**PHYSICS!!!**

By how many decibels does the sound intensity from a point source decrease if you increase the distance to it by a factor 6?
*December 1, 2010 by Molly*

**PYSCIS!!!!**

By how many decibels does the sound intensity from a point source decrease if you increase the distance to it by a factor 6?
*December 1, 2010 by Molly*

**Physics**

Taking a decibel to be an increase in pressure of 12.2%, by what factor has the pressure changed when the sound level has fallen by 8.00 decibels?
*November 15, 2012 by Steeve*

**physics**

What is the sound intensity level in decibels of ultrasound of intensity 10^5 W/m2, used to pulverize tissue during surgery
*November 27, 2012 by Jason*

**Math**

1. What are the last two digits of 9^2013? 2. Show that 5^t=2 + 3(5^t+1) - 40(5^t) is equal to zero. 3. Under certain conditions, I = 10^D/10 where D is the number of decibels of a sound and I is its intensity. If he shouts with 30 more decibels that she talks with, what is ...
*November 2, 2014 by Brianne*

**statistics**

A researcher is interested in estimating the noise levels in decibels at area urban hospitals. She wants to be 90% confident that her estimate is correct. If the standard deviation is 4.13, how large a sample is needed to get the desired information to be accurate within 0.68 ...
*November 2, 2010 by Valerie*

**physics**

what is the sound intensity level in decibels of ultrasound of intensity of 105 w/m2, used to pulverize tissue during surgery
*September 18, 2013 by Anonymous*

**Physics: Waves in Media**

By how many decibels does the sound intensity from a point source decrease if you increase the distance to it by a factor 6?
*December 7, 2010 by Amanda*

**physics**

the distance between a loudspeaker and the left ear of a listener is 2.70 m a) calculate the time required for sound to travel this distance if the air temperature is 20oC. b) assuming that the sound frequency is 523 Hz, how many wavelengths of sound are contained in this ...
*November 18, 2012 by Joe*

**Physics**

Imagine you are in an open field where two loudspeakers are set up and connected to the same amplifier so that they emit sound waves in phase at 688 Hz. Take the speed of sound in air to be 344 m/s. If you are 3.00 m from speaker A directly to your right and 3.50 m from ...
*June 4, 2012 by Mike*

**PHYSICS**

A concert loudspeaker suspended high off the ground emits 35 W of sound power. A small microphone with a 1.0 cm2 area is 50 m from the speaker. (a) What is the sound intensity at the position of the microphone? (b) How much sound energy impinges on the microphone each second?
*February 25, 2010 by Tyler*

**math**

A random sample of the houses in a particular city is selected and each of the houses in a particular city is selected and each of the house's level of radon gas is measured. The values collected are given in the table below in parts per million (ppm). 4 8 13 6 7 3 9 8 11 8 a...
*February 1, 2009 by helga*

**statistics**

A researcher is interested in estimating the noise levels in decibels at area urban hospitals. She wants to be 95% confident that her estimate is correct. If the standard deviation is 4.02, how large a sample is needed to get the desired information to be accurate within 0.58 ...
*September 2, 2011 by Laynette*

**physics help pleaseee**

In the figure below, S is a small loudspeaker driven by an audio oscillator with a frequency that is varied from 1000 Hz to 2000 Hz, and D is a cylindrical pipe with two open ends and a length of 55.0 cm. The speed of sound in the air-filled pipe is 344 m/s. (In the figure s ...
*November 16, 2008 by kelsey*

**physics**

A 10 amp fuse is connected in series to 4 identical 5 ohm resistors in parallel with each other. What is the maximum size battery that could be connected without blowing the fuse?
*February 24, 2011 by Crystal*

**Physics**

Is this statement correct: When part of sound travelled through water, wavelength and speed of sound would change because since the particles are closer together in water than in air, the speed of sound would increase which in turn would decrease the wavelength according to ...
*March 8, 2009 by Lena*

**Pre Calculus 12**

Solving problems that involve logarithms the sound at a rock concert decreases by 10% for every 5m travvelled. how far does it take for a volume of 2000 decibels to decrease to 20 decibels? i dont know what to do for this one the growth decay formula i got is A = P(X)^t/n I ...
*January 23, 2013 by Shreya*

**Physics**

An underwater microphone is used to record sounds emitted by porpoises. The minimum intensity level the instrument can record is 10 dB. Assuming a porpoise emits sound at a rate of 0.05 J/s, what will be the max distance at which the animal will still be recorded? Neglect ...
*February 21, 2010 by Mitchell*

**physics help**

Imagine you are in an open field where two loudspeakers are set up and connected to the same amplifier so that they emit sound waves in phase at 688 Hz. Take the speed of sound in air to be 344 m/s. If you are 3.00m from speaker A directly to your right and 3.50m from speaker ...
*April 19, 2010 by Anonymous*

**Physics**

There is a band who uses 10000 W to radiate sound energy in all directions. What was the intensity of sound 10 meters from this speaker? What was the sound level in dB at a distance of 10 m? At what distance from the speaker was the sound level 100 dB?
*March 12, 2015 by Josh*

**Physics**

A current of 60 mA passes through a loudspeaker of resistance 6 Ω. What is the potential difference across the resistance of the loudspeaker? 36.0 V 10.0 V 0.36 V 0.10 V Answer B seems like it would be the obvious answer..
*October 22, 2012 by Jane*

**physics**

Posted by Anonymous on Tuesday, December 2, 2008 at 12:43am. A loudspeaker is placed between two observers who are 114 m apart, along the line connecting them. If one observer records a sound level of 61.6 dB and the other records a sound level of 81.3 dB, how far is the ...
*December 2, 2008 by Anonymous*

**LA**

The short story “The Tell-Tale Heart” is told in first person point of view. How would the connection between the audience and the story most likely change if the story was told in the third person point of view? a) The audience would most likely feel less connected to the ...
*September 9, 2013 by Anonymous*

**biology**

Which bacterial plates control for: 1) If the E. coli cells were transferred correctly: 2) If the E. coli cells can grow on LB: 3) If the Ampicillin is working correctly: 4) If the “stock” E. coli cells were contaminated with plasmid: Possible choices for each number are: "-"...
*July 18, 2009 by Jenn*

**Helpp!!! physic...**

In the experiment Standing Waves,if you continue to lwer the water level after recording l(m) at the first sound resonance at fixed tuning fork frequency, you will hear the sound again but sound gets louder (second resonance). At this point, by what factor has l(m) increased? ...
*July 13, 2013 by khadijah*

**physics**

(a) By what factor is one sound more intense than another if the sound has a level 17.0 dB higher than the other? (b) If one sound has a level 32.0 dB less than another, what is the ratio of their intensities?
*July 31, 2013 by Justin*

**physics**

(a) By what factor is one sound more intense than another if the sound has a level 17.0 dB higher than the other? (b) If one sound has a level 32.0 dB less than another, what is the ratio of their intensities?
*July 31, 2013 by Justin*

**physics**

(a) By what factor is one sound more intense than another if the sound has a level 17.0 dB higher than the other? (b) If one sound has a level 32.0 dB less than another, what is the ratio of their intensities?
*August 1, 2013 by Justin*

**Science**

I`m a 5th grade student and we are haviing a Sound Science test.I`m looking for defenitions to study from.such as vibrations, decibels, frequency and questions dealing with sound travel. is there a site you could recomend? thank you, cassidy
*February 24, 2010 by Cassidy*

**Physics**

The intensity of sound from a source is measured at two points along a line from the source. The points are separated by 14.7 m, the sound level is 67.10 dB at the first point and 55.68 dB at the second point. How far is the source from the first point?
*November 27, 2008 by Shaniquaa*

**physics**

if you continue to lower the water level after recording length at the first sound resonance at fixed tuning fork frequency, you will hear the sound again but the sound gets louder(seond resonance). at this point, by what factor has length increased? why?
*July 31, 2013 by fakhrul*

**science (physics)**

1) Why is frequency an element needed in the sound industry? and 2) When there is a sound pressure level of two different sources with different frequencies, why do sound pressure levels have to be determined in each seperate frequency? 1) The sound industry sells equipment ...
*September 21, 2006 by Kat*

**physics**

At a distance of 7.5 m from a point sound source, the sound intensity level is 105 dB. At what distance is the intensity level 90 dB?
*April 13, 2012 by Anonymous*

**Physics Experiment**

In the experiment Standing Waves,if you continue to lwer the water level after recording l(m) at the first sound resonance at fixed tuning fork frequency, you will hear the sound again but sound gets louder (second resonance). At this point, by what factor has l(m) increased? ...
*July 11, 2013 by khadijah*

**alg**

Sound intensity (loudness) varies inversely as the square of the distance from the source. If a rock band has a sound intensity of 100 decibels 25 feet away from the amplifier, find the sound intensity 50 feet away from the amplifier.
*April 4, 2014 by f*

**Two Loudspeakers in a open field Pjysics**

Imagine you are in an open field where two loudspeakers are set up and connected to the same amplifier so that they emit sound waves in phase at 688 Hz. Take the speed of sound in air to be 344 m/s. If you are 3.00m from speaker A directly to your right and 3.50m from speaker ...
*May 6, 2010 by Mikhail Moskvich*

**Calculus**

Would you be able to help me with a couple of questions? thanks in advanced! 1. I am given the graph f(x)=x^2-2x. I have to draw a line tangent to the point (0,0). Then, I have to estimate the slope at that point. how would I go about answering this question? would I first ...
*April 10, 2014 by Sarah*

**physics**

What are the decibels 917m away from a 35.5 W sound source?
*November 19, 2013 by Sara*

**physics**

What are the decibels 917m away from a 35.5 W sound source?
*November 19, 2013 by SDW*

**Physics**

A 60 watt light bulb in a household circuit at 120 V carries a current of 0.500 amp. (An amp was defined in class as a way to measure charge movement. One amp is one coulomb per second.) How many electrons move through this light bulb in five minutes?
*March 7, 2011 by Anonymous*

**Physics URGENT!!!**

A train sounds its horn as it approaches an intersection. The horn can just be heard at a level of 59 dB by an observer 14 km away. (a) What (b) What intensity level of the horns sound is observed by someone waiting at an intersection 46 m from the train? Treat the horn as a ...
*December 4, 2012 by Tia*

**Physics URGENT!!!**

A train sounds its horn as it approaches an intersection. The horn can just be heard at a level of 59 dB by an observer 14 km away. (a) What is the average power generated by the horn? (b) What intensity level of the horns sound is observed by someone waiting at an ...
*December 6, 2012 by Anonymous*