Complete question :
The loudness of a jack hammer is 96 dB. Its sound intensity is about 0.004.
The loudness of a compactor is 94 dB. Its sound intensity is about 0.0025.
The sound intensity of the jack hammer is about 1.6 times the sound intensity of the compactor.
The loudness of a pile driver is 112 dB. About how many times the sound intensity of the jackhammer is the sound intensity of a pile driver? Round to the nearest ten.
Answer:
40
Explanation:
Given that:
Sound intensity of jackhammer = 0.004
Sound intensity of compactor = 0.0025
Sound intensity of jackhammer is about 1.6 times the sound intensity of a compactor
Each factor of 10 in intensity corresponds to 10dB
Pile driver with loudness of 112dB ; 112 / 10 = 11.2
Hence, 10^11.2 = 1.58489 * 10^11
Hence, sound intensity (I) in watts per m²
I = 1.58489 * 10^11 * 10^-12
I = 1.58489 * 10-1
I = 0.158489
Comparing the intensity of pile driver and jackhammer :
Intensity of piledriver / Intensity of jackhammer
0.158489 / 0.004
= 39.622
= 40 (nearest ten)