Answer
(a) $0.35KHz$
(b) greater frequency
(c) $0.38KHz$
Work Step by Step
(a) The frequency heard by Betsy can be calculated as
$f^{\prime}=(\frac{1}{1-u/v})f$
We plug in the known values to obtain:
$f^{\prime}=(\frac{1}{1-\frac{24}{343}})(330)$
$f^{\prime}=0.35KHz$
(b) Jim hears a greater frequency as Jim is an observer moving towards the source.
(c) The frequency heard by Jim can be calculated as
$f^{\prime \prime}=(1+u/v)f^{\prime}$
We plug in the known values to obtain:
$f^{\prime \prime}=(1+\frac{24}{343})(355)=0.38KHz$
