In: Physics
A music fan at a swimming pool is listening to a radio on a diving platform. The radio is playing at a constant frequency tone when this person, clutching the portable radio, jumps. Describe the observed frequency or pitch for the following three observers. Explain your reasoning.
a) The person holding the radio
b) A person left behind on the platform
c) A person below the platform floating on a rubber raft
above problem is purely based on sound phenomena which will better described by one of the favorite acoustic phenomena called Doppler effect.
The Doppler effect causes the received frequency of a source (how it is perceived when it gets to its destination) to differ from the sent frequency if there is motion that is increasing or decreasing the distance between the source and the receiver.
1. For person holding the radio, did not feel any doppler effect because the source(radio) and observer are moving together.
2. For person left behind on the platform, the frequency increases in the case when we move towards the source or the source moves towards us. That is, the frequency decreases when we move away from the source or the source moves away from us.
Therefore,
F0 is smaller than fs, because the frequency decreases as it is moving away from the source.
3. Similarly, a person below the platform floating on a rubber raft, observes frequency is higher than fs by source is moving towards him in the other case because it is moving towards the source.