Question

The speed of ultrasonic sound in air is
A. $3 \times {10^8}m{s^{ - 1}}$
B. $340m{s^{ - 1}}$
C. $1500m{s^{ - 1}}$
D. $4500m{s^{ - 1}}$

Answer 1

Discuss about the Characteristics of the types of sound and choose the correct answer accordingly.

Complete step by step answer: Infrasonic waves- These are the waves which are inaudible to the human ear. Their frequency ranges are below $20Hz$
Ultrasonic waves- These are the waves which are also inaudible to the human ear. Their frequency ranges are above $20000Hz$ and Speed of sound depends on the properties of the medium through which it travels. Thus, the speed of ultrasonic sound in air $340m{s^{ - 1}}$.
The audible waves which are heard by the human ear and its frequency ranges between $20Hz$ and $20000Hz$.
So, Thus the Correct Answer is Option B

Additional Information:
The Sound waves are independent upon the wave characteristics such as amplitude, period, and frequency. Sound waves travel faster in solid, fast in liquid and slow in air and It cannot travel in vacuum.
Sound waves travel at the same speed of all the frequencies in ideal gases and in air. The Presence of carbon dioxide and dust particles in air affect the speed but of negligible significance.
The speed of sound in air depends only on temperature not on the pressure or density. The Sound wave travels in air as longitudinal waves.However in solid, sound wave travels both in transverse waves and longitudinal waves. Velocity through a given medium is directly related to stiffness of that medium and inversely related to the density.

Note: Wavelength is inversely proportional to its frequency and Wave speed is calculated by multiplying the frequency by its wavelength.