Ask Experts Questions for FREE Help !
Ask
    dragosani's Avatar
    dragosani Posts: 6, Reputation: 1
    New Member
     
    #1

    Mar 14, 2009, 12:59 PM
    Intensity of sound; decibels
    At a rock concert, a dB meter registered 130dB when placed 2.8m in front of a loudspeaker on the stage. A.) What was the power output of the speaker assuming uniform spherical spreading of sound and neglecting absorption in the air? B.) How far away would the sound level be a somewhat resonable 90dB?
    I've solved A part and got the intensity to be 10w/m2.

    130db=10log(I/ 10^-12) @ 2.8m
    10^13= I/ 10^-12
    10=I

    I know I'm supposed to be finding r for part b. I know I is proportional to (1/r)^2 but I don't know how to use that to come up with the answer.
    Please explain how to do this second part. Thank you.
    sami hamed's Avatar
    sami hamed Posts: 1, Reputation: 1
    New Member
     
    #2

    Feb 28, 2010, 05:38 PM
    The decible level of a piano is 60db.
    What is the intensity of this sound in w/m 2?

Not your question? Ask your question View similar questions

 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Is 143.7 Decibels loud for a sound system? [ 7 Answers ]

Hi I was wondering if 143.7 decibles loud for a car sound system. And how does it all work?

No sound while watching television.sound when playing video games [ 4 Answers ]

I have no Idea what the problem could be, but if I try to watch television, which is cable, I cannot hear the sound on the television, but If I play video games, then you can hear the sound perfectly... So, it cannot be a problem with the speakers inside the television.. Could it be the cable? What...

Physical optics, intensity and power [ 1 Answers ]

Dear Mr. Thanks for the great site. I've a question in Physical optics for pre-pharmacy students. My question is, sunlight strikes a solar panel communication satellite at an angle of 65 degrees and at a power of 3200 watts, what's the power and intensity when the angle becomes 35 degrees...

Luminous intensity [ 1 Answers ]

Is luminous intensity also basic quanties?


View more questions Search