contestada

As you stand near a railroad track, a train passes by at a speed of 34.5 m/s while sounding its horn at a frequency of 215 Hz. What frequency do you hear as the train approaches you and what frequency while it recedes? Take the speed of sound in air to be 341 m/s.

Respuesta :

Answer:

when train is approaching then the frequency is 239.2 Hz

when train is moving away  then the frequency is 195.25 Hz    

Explanation:

given,

speed of train = 34.5 m/s

Frequency of sound = 215 Hz

speed of sound = 341 m/s

a) when train is approaching

  [tex]f_1 = f(\dfrac{V}{V-V_t})[/tex]

  [tex]f_1 = 215(\dfrac{341}{341-34.5})[/tex]

          f₁ = 239.2 Hz                                

when train is approaching then the frequency is 239.2 Hz

b) when the train is moving away

  [tex]f_2 = f(\dfrac{V}{V+V_t})[/tex]

  [tex]f_2 = 215(\dfrac{341}{341+34.5})[/tex]

         f₂ = 195.25 Hz      

when train is moving away  then the frequency is 195.25 Hz