<P> The siren on a passing emergency vehicle will start out higher than its stationary pitch , slide down as it passes , and continue lower than its stationary pitch as it recedes from the observer . Astronomer John Dobson explained the effect thus : </P>
<P> The siren on a passing emergency vehicle will start out higher than its stationary pitch , slide down as it passes , and continue lower than its stationary pitch as it recedes from the observer . Astronomer John Dobson explained the effect thus : </P>
according to the doppler effect the sound of a police car siren is
according to the doppler effect the sound of a police car siren is
start out higher than its stationary pitch , slide down as it passes , and continue lower than its stationary pitch as it recedes from the observer
start out higher than its stationary pitch , slide down as it passes , and continue lower than its stationary pitch as it recedes from the observer