Chapter 26, Problem 4A

Distinguish between infrasonic and ultrasonic sound.

To determine

The difference between infrasonic & ultrasonic sound.

Answer to Problem 4A

The sound of frequency below 20 hertz is infrasonic sound & the frequency above 20,000 hertz is known as ultrasonic sound .

Explanation of Solution

Introduction: Sound is a form of energy. It is measured in hertz. There are different sound which are differentiated by frequency of sound. The average range of young person’s $20to20,000Hz$ .

The sound wave frequency below 20 hertz are known as infrasonic sound & the sound wave frequency above 20,000 hertz are known as ultrasonic sound.

Let f is the frequency of sound wave then :

  $\begin{array}{l}f<20Hz(\text{infrasonic sound )}\\ f>20,000Hz(\text{ultrasonic sound )}\end{array}$

Conclusion: The infrasonic has sound frequency below 20 Hz & ultrasonic has above 20,000 Hz.