Chapter 5.4, Problem 132AYU

To determine

The loudness of a diesel truck in decibels when the diesel truck is travelling at $40$ miles per hour, $50$ feet away, intensity $10$ times that of a passenger car travelling $50$ miles per hour, $50$ feet away, whose loudness is $70$ decibel and loudness $L\left(x\right)$ is given by $L\left(x\right)=10\log \frac{x}{I_0}$, where $x$ is the intensity of sound measured in watts per square meter and $I_0={10}^{-12}$ watt per square meter is the least intense sound that human ear can detect.