91Ó°ÊÓ

• i)The frequency of sound wave is$f=4.46×{10}^{3}Hz$
• ii) The distance between two ridges is$d=9.20cmor0.092m$

Use the concept of interference and standing waves and can find the wavelength from the distance between two ridges. The equation of speed-related to the frequency and wavelength of a wave will give us the speed of sound in the gas.

Formula:

The speed of a standing wave,$V=\mathrm{λ}f$ (i)

Given that the ridges are formed at the nodes of standing waves. So, the distance between ridges will represent the distance of half wavelength.

Hence, the wavelength of sound waves inside Kundt’s tube is
$\mathrm{λ}=2×d$
= 0.184m

Using equation (i), the speed of sound waves inside the tube can be given as:
$$\begin{gathered} V=0.184×4.46×{10}^3 \\ =820.64 \\ ~821\frac{m}{s} \end{gathered}$$

Hence, the value of the speed of the sound waves is$821\frac{m}{s}$