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(iii) Two students use this method to investigate sound from a moving source. S...

Jun 12, 2024

Solution

The experiment involves a buzzer moving in a horizontal circular path, which means it is undergoing circular motion. The sound heard by Student A (who is spinning the buzzer) and Student B (who is standing several meters away) will differ due to the Doppler effect

When Student A spins the buzzer at a slow speed, the frequency of the sound waves reaching Student B will be slightly higher when the buzzer is moving towards her and slightly lower when it is moving away. This is because the relative velocity between the buzzer and Student B changes as the buzzer moves in a circle

When Student A spins the buzzer at a high speed, the Doppler effect becomes more pronounced. The frequency of the sound waves reaching Student B will be significantly higher when the buzzer is moving towards her and significantly lower when it is moving away

Student A, who is spinning the buzzer, will hear a constant frequency because the buzzer is at a constant distance from her and there is no relative motion between her and the buzzer

The difference in the sounds heard by Student A and Student B can be explained by the Doppler effect, which states that the frequency of a wave changes for an observer moving relative to the source of the wave

Answer

The sound heard by Student A is constant, while the sound heard by Student B varies due to the Doppler effect.

Key Concept

Doppler Effect: The change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source.

Explanation

The Doppler effect causes the frequency of the sound waves to change for Student B as the buzzer moves towards and away from her, while Student A hears a constant frequency because there is no relative motion between her and the buzzer.