Thursday

July 24, 2014

July 24, 2014

Number of results: 53,463

**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*

**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*

**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*

**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**

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 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**

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*

**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*

**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**

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**

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**

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*

**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*

**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*

**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*

**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*

**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**

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*

**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 - 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*

**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**

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*

**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**

(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*

**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*

**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*

**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**

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*

**college physics**

The sound level when one child is talking in a room is 60.0 dB. What would be the sound level if all 20 children talk at the same time in the same room? Assume each child talks equally loudly.
*January 18, 2014 by bano*

**physics**

1.) The average sound intensity inside a busy neighborhood restaurant is 3.*10^-5 W/M^2. How much energy goes into each ear (area = 2.1 * 10^-2 m^2) during a one hour meal? 2.) A member of an aircraft maintenance crew wears protective earplugs that reduce the sound intensity ...
*December 12, 2010 by David*

**alg 2**

The sound level in decibles, B, can be found using the equation B=10 log(I/10^-12). what is the sound intensity when the decible level is 90? pleaseeeeeeeeeeee helppppppppppppppppppp
*June 16, 2008 by URGENT!!!!!!!!!*

**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**

A grade-school teacher insists that the the overall sound level in his classroom not exceed 64 dB at his location. There are 25 students in his class. If each student talks at the same intensity level, and they all talk at once, what is the highest sound level at which each ...
*April 5, 2011 by chris giordano*

**Math**

Log functions: A new car has an interior sound level of 70 dB at 50 km h. A second car, at the same speed, has an interior sound level that is two times more intense than that of the new car. Calculate the sound level inside the second car.
*May 27, 2011 by Aimee*

**Physics**

You're at a concert at a distance of 10m away from the band and their sound level is 120dB. How far back do you have to move if you want the sound level to be 85 dB? I tried using 85=(10/r1)^2, but this doesn't seem to be working.
*October 22, 2008 by Ziyi*

**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*

**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- Elena please help!**

An interstate highway has been built though a poor neighborhood in a city. In the afternoon, the sound level in a rented room is 114.0 dB as 172 cars pass outside the window every minute. (a) What is the sound intensity during the day ? (Reminder: If you choose to use ...
*December 5, 2012 by Mary*

**Physics**

As measured from centre ice, a single wildly cheering hockey fan can produce a sound intensity level of 60dB. What sound intensity level would be produced by 20 000 cheering fans? --------- If sound waves travel through the ground with an average speed of 6150 m/s and a ...
*May 15, 2012 by HelpMeWithPhysics*

**physics**

A member of an aircraft maintenance crew wears protective earplugs that reduce the sound intensity by a factor of 355. When a jet aircraft is taking off, the sound intensity level experienced by the crew member is 72 dB. What sound intensity level would the crew member ...
*December 3, 2011 by Marco*

**Physics**

A jet engine produces a sound level of 150 dB from a distance of 30 m (assuming spherical dissipation). The average human ear has an effective area of 12.0 cm2. What is the sound level at 60 m from a jet engine is? What would the power intercepted by an unprotected ear at 60 m...
*May 27, 2014 by Teagan*

**STUPID PHYSICS**

As measured from centre ice, a single wildly cheering hockey fan can produce a sound intensity level of 60dB. What sound intensity level would be produced by 20 000 cheering fans? --------- If sound waves travel through the ground with an average speed of 6150 m/s and a ...
*May 15, 2012 by HelpMeWithPhysics*

**Physics(Please help)**

The intensity (in W/m2) of one sound is 4.83 times as great as the intensity of another sound. Relative to the quieter sound, what is the intensity level â of the louder sound? I am not sure how to start this. Thank you.
*June 21, 2012 by Hannah*

**Functions**

Problem solving with logarithmic functions: A new car has an interior sound level of 70 dB at 50 km h. A second car, at the same speed, has an interior sound level that is two times more intense than that of the new car. Calculate the sound level inside the second car.
*May 26, 2011 by Aimee*

**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 quality of a musical tone has to do with a variety of which of the following? A) amplitudes.B) sound speeds.C) intensities.D) decibels.E) harmonics.
*April 30, 2012 by Jim*

**algebra**

find the number of decibels for the power of the sound. round to nearest decibel. a rock concert 5.34*10^-6 watts/cm^2 D= Db
*October 24, 2012 by missfubu-c*

**math **

2.58*10^(-5)watts/cm2 find the number of decibels for the power of the sound given. Round to the nearest decibel.
*February 10, 2013 by Andrzej*

**Physics SOUND**

What is the resultant sound level when an 80-dB and an 85-dB sound are heard simultaneously?
*May 3, 2008 by Anonymous*

**science grade 7**

-80 decibels more than or less than -20 decibels??
*October 29, 2012 by rawr... im a dinosaur.... rawr *

**math**

Could someone help explain what I am to do? The amount of background noise is important to television news reporters. One station developed the formula n= -t^2 + 12t +54 showing the noise level in decibels (N) as it relates to the time after the speaker stops talking in ...
*September 8, 2009 by sam*

**physics**

19 cars in a circle at a boom box competition produce a 130 dB sound level at the center of the circle. What is the average sound level(dB) produced there by each, assuming interference effects can be neglected?
*July 31, 2013 by Justin*

**physics**

19 cars in a circle at a boom box competition produce a 130 dB sound level at the center of the circle. What is the average sound level(dB) produced there by each, assuming interference effects can be neglected?
*July 31, 2013 by Justin*

**physics**

19 cars in a circle at a boom box competition produce a 130 dB sound level at the center of the circle. What is the average sound level(dB) produced there by each, assuming interference effects can be neglected?
*August 1, 2013 by Justin*

**Physics**

18 cars in a circle at a boom box competition produce a 105 dB sound level at the center of the circle. What is the average sound level produced there by each, assuming interference effects can be neglected? dB = ?
*February 8, 2014 by ddsMom*

**Math**

Find the number of decibels for the power of the sound. Round to the nearest decibel. A rock concert, 5.19 10-6 watts/cm2 D= ? db
*July 15, 2011 by Lee Ann*

**algebra**

Find the number of decibels for the power of the sound. Round to the nearest decibel. A rock concert, 5.4 10-6 watts/cm2
*October 30, 2011 by suzie*

**algebra**

Find the number of decibels for the power of the sound. round to the nearest decibel. A rock concert, 5.35x 10^4 watts/cm^2
*July 24, 2012 by Nancy*

**Algebra**

Find the number of decibels for the power of the sound. Round to the nearest decibel. A rock concert, 5.3 10-6 watts/cm2
*August 3, 2012 by Deb*

**algebra**

Find the number of decibels for the power of the sound given. Round to the nearest decibel. A rocket engine, 2.42 * 10^5 watts cm^2 what is the db?
*November 11, 2013 by lisa*

**physics**

A sound registers 77.9 decibels on a detector. What is the intensity in W/m2? Assume the threshold of human hearing is 1.0×10-12 W/m2. Give your answer in picowatts/m2. 1 pW = 1×10-12 W/m2
*June 21, 2014 by allen*

**ALGEBRA**

Find the number of decibels for the power of the sound. Round to the nearest decibel. A rock concert, 5.21 multiplied by 10-6 watts/cm2
*April 16, 2012 by Randy*

**Math**

Find the number of decibels for the power of the sound. Round to the nearest decibel. A rock concert, 5.35 10-6 watts/cm2 D =______ dB
*October 30, 2012 by Ms. Jackie*

**math**

Find the number of decibels for the power of the sound given. Round to the nearest decibel. A rocket engine, 2.65 times 10^-5 watts/cm^2
*March 16, 2013 by Andrew*

**math**

Find the number of decibels for the power of the sound given. Round to the nearest decibel. A rocket engine, 2.65 times 10^-5 watts/cm^2
*March 17, 2013 by Andrew*

**Algebra**

find the number of decibels for for the power of the sound given. Round to the nearest decibel. a rocket engine, 2.4 X 10 -5 watts/cm2
*February 14, 2014 by Adrienne*

**physics**

In a pig-calling contest, a caller produces a sound with an intensity level of 110 dB. How many such callers would be required to reach the pain level of 120 dB?
*November 26, 2011 by jazz*

**Physics**

This time I have two questions: #1.A recording engineer works in a soundproofed room that is 49.7 dB quieter than the outside. If the sound intensity in the room is 2.66 x 10-10 W/m2, what is the intensity outside? #2.A listener increases his distance from a sound source by a ...
*December 5, 2006 by Jena*

**Math**

At a concert, the loudness of sound, L, in decibels, is given by the equation L=10log(I/I_o), where I is the intensity, in watts per square metre, and I_o, is the minimum intensity of sound audible to the average person, or 1.0 x 10^-12 W/m^2. a) The sound intensity at a ...
*May 20, 2009 by Jus*

**Math**

At a concert, the loudness of sound, L, in decibels, is given by the equation L=10log(I/I_o), where I is the intensity, in watts per square metre, and I_o, is the minimum intensity of sound audible to the average person, or 1.0 x 10^-12 W/m^2. a) The sound intensity at a ...
*May 20, 2009 by Jus*

**Physics - okay, turns out I need help once more**

but this is the last problem, so I'll be done after thins one. :) You're at a concert at a distance of 10m away from the band and their sound level is 120dB. How far back do you have to move if you want the sound level to be 85 dB? I tried using 85=(10/r1)^2, but this doesn't ...
*October 21, 2008 by Ziyi*

**physics**

19 cars in a circle at a boom box competition produce a 130 dB sound level at the center of the circle. What is the average sound level(dB) produced there by each, assuming interference effects can be neglected? Please someone help me to solve this problem. Thanks a lot.
*August 2, 2013 by Justin*

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