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

  1. 👍 0
  2. 👎 0
  3. 👁 148
asked by allen
  1. 77.9 = 10 log I/10^-12 = log I/10^-11

    7.79 = log (I*10^12)

    10^7.79 = I * 10^12

    6.17 * 10^7 = I * 10^12

    I = 6.67 * 10^-5 W/m^2

    1. 👍 0
    2. 👎 0
    posted by Damon

Respond to this Question

First Name

Your Response

Similar Questions

  1. 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

    asked by Sarah on February 21, 2016
  2. 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

    asked by Ryan on November 30, 2015
  3. 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

    asked by Donna on February 16, 2014
  4. 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,

    asked by math challenged on April 4, 2011
  5. 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

    asked by Donna on February 17, 2014
  1. 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

    asked by Ana on March 1, 2010
  2. 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?

    asked by Amanda on March 29, 2008
  3. 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?

    asked by Help!! on April 18, 2010
  4. 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

    asked by sara on March 27, 2012
  5. 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

    asked by Brianne on November 2, 2014

More Similar Questions