Question

A woman is travelling in a car at a speed of 25 m/s. She is moving away from a source producing a sound of 512hz.



a.Calculate the frequency of sound heard by her. (speed of sound in air = 340 m/s)

Answer 1

Answer:

This is dopplers effect

in this case

$f_{observed} = (\frac{v-v_o}{v} )*f_o\\\\f_{observed} = (\frac{340-25}{340})*512 Hz = \frac{315}{340}*512Hz = 474.35 Hz$

frequency heard by the woman is 474.35 Hz