Question

What is the decibel level of heavy city traffic with intensity ${10}^{-3}$watts per square inch?

Short answer

The decibel level of heavy city traffic is$90db$.

Step-by-step solution

Step 1. Given information.

The given intensity is ${10}^{-3}$watts per square inch.

ere the loudness level, D, measured in decibels, of a sound of intensity, I, measured in watts per square inch is

$D=10\log \left(\frac{I}{{10}^{-12}}\right)$.

Step 2. Finding the decibel level.  

Here the intensity is ${10}^{-3}$watts per square inch then the decibel level is

$$\begin{gathered} D=10\log \left(\frac{I}{{10}^{-12}}\right) \\ =10\log \left(\frac{{10}^{-3}}{{10}^{-12}}\right) \\ =10\log \left({10}^9\right) \\ =9\times 10 \\ =90 \end{gathered}$$

Therefore, the decibel level of heavy city traffic is$90db$.