1. A railroad train is traveling at 30 m/s. The locomotive whistle emits a loud

Question

1. A railroad train is traveling at 30 m/s. The locomotive whistle emits a loud tone at
frequency 440 Hz.
a) what is the wavelength of the sound waves in front of the locomotive?
b) what is the wavelength of the sound waves behind the locomotive?
c) what is the frequency of the sound heard by a stationary listener in front of
the locomotive?
d) what is the frequency of the sound heard by a passenger on a second train
that is moving at 15 m/s with respect to the ground, headed toward the first
train? (In other words, the train with the whistle is traveling at 30 m/s and
the train with the observer is traveling in the opposite direction at 15 m/s.
The trains are on parallel tracks, so they won’t crash into each other)
e) what is the frequency of the sound heard by the passenger in part (d) after
the trains have passed each other?

Explanation / Answer

(a)

 velocity of sound=343 m/s

  Velocity of train=30 m/s

  f=440 Hz

  V(net)=343-30=313 m/s

  V=f

  =313/440

     =0.7114 m or 71.14 cm or 711.4 mm

(b)

  Velocity expanded by the factor= 343+30=373 m/s

     =373/440

       =0.84773 m or 84.773 cm or 847.73 mm

(c)

 The infront observer would experience the frequency = 440 x343/(343-30) Hz

                                                                                =482.173 Hz

(d)

   Frequency=440*(343+15)/(343-30)

                 =503.259 Hz

(e)

 After train has passed each other:

  f=440*(343-15)/(343+30)

    =386.917 Hz

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.