Question

A train blows its whistle as it moves rapidly towards a stationary observer. Which of the following best describes the sound of the whistle as heard by the observer in comparison to the sound as heard by a passenger on the train?

a. The sound heard by the observer will be the same as the sound heard by the passenger.
b. The sound heard by the observer will be of a higher volume than the sound heard by the passenger.
c. The sound heard by the observer will be higher in pitch than the sound heard by the passenger.
d. The sound heard by the observer will be lower in pitch than the sound heard by the passenger.

Answer 1

The sound of the train's whistle as heard by a stationary observer compared to a passenger on the train will be higher in pitch due to the Doppler Effect.

Step-by-step explanation:

The phenomenon that describes the change in pitch of a sound due to the relative motion between the observer and the source of the sound is known as the Doppler Effect. When the question asks what would be heard by a stationary observer as a train approaches with a whistle, we're looking at the Doppler Effect in action. The sound heard by the observer will be higher in pitch than the sound heard by a passenger on the train. This is because the sound waves are compressed due to the train moving towards the observer, which increases the frequency of the sound waves reaching the observer's ear, resulting in a higher pitch.