Recall that decibels are used to measure the loudness of sou

Recall that decibels are used to measure the loudness of sound, L, and that L= 10log(1/1) where I is the intensity of the sound in watts per metre^2(W/m^2), and I =10^-12(W/m^2)

a) Determine the intensity for the sound level emitted by the siren is 110B,

b) A military jet has a sound intensity of 10^2 W/m^2, determine the loundness of the jet in dB

Solution

L=10 Log (I/I₀) Where I₀ is the threshold intensity the value of which is given as 10^-12 W/m²
a) Siren Loudness = 110dB
so L=110
Putting this value of L in the given equation,
110=10 Log (I/I₀)
11= Log (I/10^-12)
I/10^-12=10¹¹
I=10^-12 * 10¹¹ = 0.1 W/m²

b) Intensity of military jet = I = 10² W/m²
Loudness L=10*Log (10²/10^-12) = 10 * Log (10¹⁴) = 10*14 =140 dB
Thus loudness of the jet = 140 dB