Chapter 8.6, Problem 79SR

To determine

To explain: Explain the intensity of a whisper to a normal conversation

Explanation of Solution

Given information:

The table below:

Watts Per Square Meter	Common Sounds
${10}^{(-11)}$	Rustling leaves
${10}^{(-10)}$	Whisper
${10}^{(-6)}$	Normal conversation
${10}^{(-5)}$	Busy street traffic
${10}^{(-4)}$	Vacuum cleaner
${10}^{(-1)}$	Front rows of rock concert
${10}^{(1)}$	Threshold of plan
${10}^{(2)}$	Military jet takes off

Proof:

Consider the table below:

Watts Per Square Meter	Common Sounds
${10}^{(-11)}$	Rustling leaves
${10}^{(-10)}$	Whisper
${10}^{(-6)}$	Normal conversation
${10}^{(-5)}$	Busy street traffic
${10}^{(-4)}$	Vacuum cleaner
${10}^{(-1)}$	Front rows of rock concert
${10}^{(1)}$	Threshold of plan
${10}^{(2)}$	Military jet takes off

The strategy is to compare the intensity of a whisper to a normal conversation.

Here the intense of sound for whisper is $:{10}^{-10}$ .

Again, the intense of sound for normal conversation is: ${10}^{-6}$ .

Hence, the number of items will be:

  $\begin{array}{cc}\frac{{10}^{-6}}{{10}^{-10}}=& {10}^{-6-(-10)}\\ =& {10}^{-6+10}\\ & ={10}^4\end{array}$

Therefore, the normal conversation is ${10}^4$ times more intense than sound from whisper.