Questions: A stereo speaker produces a pure "G" tone, with a frequency of 392 Hz.
What is the period T of the sound wave produced by the speaker?
T=
s
What is the wavelength λwater of the same sound wave as it enters some water, where it has a speed of about 1480 m / s ?
λwater=
m
What is the wavelength λair of this sound wave as it travels through air with a speed of about 341 m / s ?
λair=
m
Transcript text: A stereo speaker produces a pure "G" tone, with a frequency of 392 Hz.
What is the period $T$ of the sound wave produced by the speaker?
$T=$ $\square$
$s$
What is the wavelength $\lambda_{\text {water }}$ of the same sound wave as it enters some water, where it has a speed of about $1480 \mathrm{~m} / \mathrm{s}$ ?
\[
\lambda_{\text {water }}=
\]
$\square$
m
What is the wavelength $\lambda_{\text {air }}$ of this sound wave as it travels through air with a speed of about $341 \mathrm{~m} / \mathrm{s}$ ?
\[
\lambda_{\text {air }}=
\]
$\square$
m
Solution
Solution Steps
Step 1: Calculate the Period \( T \) of the Sound Wave
The period \( T \) of a sound wave is the reciprocal of its frequency \( f \). Given the frequency \( f = 392 \) Hz, we can calculate the period using the formula:
\[
T = \frac{1}{f}
\]
Substituting the given frequency:
\[
T = \frac{1}{392} \approx 0.0026 \text{ s}
\]
Step 2: Calculate the Wavelength \( \lambda_{\text{water}} \) in Water
The wavelength \( \lambda \) of a sound wave is given by the formula:
\[
\lambda = \frac{v}{f}
\]
where \( v \) is the speed of sound in the medium and \( f \) is the frequency. For water, \( v = 1480 \) m/s and \( f = 392 \) Hz. Substituting these values:
\[
\lambda_{\text{water}} = \frac{1480}{392} \approx 3.7755 \text{ m}
\]
Step 3: Calculate the Wavelength \( \lambda_{\text{air}} \) in Air
Using the same formula for wavelength, but with the speed of sound in air \( v = 341 \) m/s:
\[
\lambda_{\text{air}} = \frac{341}{392} \approx 0.8699 \text{ m}
\]