Question

What is the sound level for a noise that has an intensity of 7.6 × 10-4 watts/m2?

Answer 1

The sound level for a noise is 88.9 dB.

Explanation:

Given : Intensity of noise is
`7.6* 10^(-4)Wm^(-2)`.

To find : What is the sound level for a noise?

Solution :

The range of the sound intensity is the threshold of hearing which is

`I_o=1* 10^(-12)Wm^(-2)`

Intensity of noise is
`I=7.6* 10^(-4)Wm^(-2)`

The intensity level in d B of a sound of intensity I is defined as:

`I_s=(10dB)\log_(10)((I)/(I_o))`

Substitute the values,

`I_s=(10dB)\log_(10)((7.6* 10^(-4))/(1* 10^(-12)))`

`I_s=(10dB)\log_(10)({7.6* 10^(8))`

`I_s=(10dB)(8.89)`

`I_s=88.9dB`

Therefore, The sound level for a noise is 88.9 dB.