Question

A police car is moving to the left at 34m/sec while its siren is emitting a 600Hz tone. What tone would you hear if you were parked along side the road

Answer 1

Answer:

$545.89\ \text{Hz}$

Explanation:

$v_o$ = Velocity of observer = 0

$v_s$ = Velocity of source = 34 m/s

v = Speed of sound in air = 343 m/s

f = Emitted frequency = 600 Hz

Doppler effect will be observed

$f_o=f(\dfrac{v+v_o}{v+v_s})\\\Rightarrow f_o=600(\dfrac{343+0}{343+34})\\\Rightarrow f_o=545.89\ \text{Hz}$

The frequency heard will be $545.89\ \text{Hz}$.