Question

expensive amplifier a is rated at 290 W and modest amplifier b is rated at 36 W. estimate the sound level in decibels you would expect at a point 2.5 m from a loud speaker connected in turn to each amp.

Expensive___
Modest____

Will the expensive amp sound twice as loud as the modest?

yes or no

Answer 1

intnesity level B = 10 dB log(I/Io)

where Io = 10^-12m W/m^2

and I = power/area

area = 4pir^2

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so here, for expensive amplifier

Intenisty I = 290/(4*3.14*2.5*2.5) = 3.694 Watts

so Intensity level B = 10 dB * log ( 3.694/10^-12)

B = 125.674 dB

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for modest one, Intensity level B = 10 dB *log(36/(4pi*2.5*2.5)/10^-12)

B = 116.61 dB

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no expensive one will not make twice loud that of modest one, it makes just a little more