All Solutions
Page 511: Practice Problems
$f_{listener}=f_{source}dfrac{v_{sound}pm v_{listener}}{v_{sound}pm v_{source}}$
The rules are:
If the listener is travelling towards the source, the sign of $v_{listener}$ is positive. If it’s moving away, then it is negative.
Furthermore, if the source is moving towards from the listener, the sign of $v_{source}$ is negative. If the source is moving away from the listener, it is positive.
$451=440left(dfrac{343+v_{listener}}{343}right)$
Solve for $v_{listener}$
$$
v_{observer}=8.58;m/s
$$
v_{observer}=8.58;m/s
$$
$f_{listener}=f_{source}dfrac{v_{sound}pm v_{listener}}{v_{sound}pm v_{source}}$
The rules are:
If the listener is travelling towards the source, the sign of $v_{listener}$ is positive. If it’s moving away, then it is negative.
Furthermore, if the source is moving towards from the listener, the sign of $v_{source}$ is negative. If the source is moving away from the listener, it is positive.
Plug-in the given values and solve for $f_{source}$
$375=f_{source}left(dfrac{343+25}{343}right)$
Solve for $f_{source}$
$$
f_{source}=350;Hz
$$
f_{source}=350;Hz
$$