eppeste direction toward the source, then the frequency of the sound heard by the observer is

$f_e=(\frac{c+v_0}{c-v_s})r_s$

where $c$ is the speed of sound, about $332\frac{m}{s}.($This is the Doppler effect.$)$ Suppose that, at a particular moment, reu are in a tren trie of at at mint. has a freaueney of $490Mz.$ At that instant, what is the perceived frequency that you hear? $($Reund reur anmwer to ene decima' p$.$ pe$.).$

How fast is it changing? $($Round your answer to two decimal places.$)H\frac{z}{s}$