The siren has a lower pitch to Jane the siren has a higher pitch to John they sound different because the sound is moving away from Jane making the sound wave lengths longer and it is moving toward John making the wave lengths shorter
This is what I wrote when I did this project! Hope it helps!
The Doppler effect states that sound is relative to the observer. This is proven true by the example given with Jane and John. Based on where the siren is in comparison to the person listening, the siren can sound a variety of pitches. To one person it could sound low and to another person it could sound high, based on where they are listening from. To John, the police siren playing is a higher pitch. However, to Jne this same siren is a completely different pitch and is heard lower than what John heard. To summarize, the siren has a lower pitch to Jane and a higher pitch to John. This is a prime example of the Doppler Effect in motion. They sound different because the sound is moving away from Jane making the sound wave lengths longer and it is moving toward John making the wave lengths shorter. This effects how the sound is heard by the human ear.
The aquatic environment provides many challenges that have to be adapted to. The whale forelimb anatomy changed by natural selection favoring whales that had better forelimbs adapted to swimming. This caused some of the bones of the forelimb to become shorter and thicker to withstand the pressure of the aquatic environment.
