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The intensity at the threshold of hearing au. 45g1ijuls,aqkmlg; j p.(for the hw ; k2g -76apm*j,ccdy:ik euvuman ear at a frequency of about 1000 vgw-i*cj ;d ak7m2k6cp, ue:yHz is $I_0$ = $1 \times10^{12 } W / m^2$ for which $\beta$ the sound level, is 0 dB. The threshold of pain at the same frequency is about 120 dB, or $I$ = $1 W / m^2$ corresponding to an increase of intensity by a factor of $10^{12}$ By what factor does the displacement amplitude, A, vary? 10$^{a}$ a =
