The two correct answers that explain situations in which two observers (A and B) would measure different frequencies for the same vibrating object are:
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Observer A and Observer B are stationary but at different distances from the vibrating object. - This would not normally cause a difference in frequency measurement directly, as frequency is an inherent property of the source. However, due to intensity effects or other factors, the perceived loudness/pitch by different observers may vary slightly, but this is less directly related to frequency itself.
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Observer A and Observer B are moving at different speeds relative to each other. - This would lead to the Doppler effect, where the frequency measured by each observer can differ based on their respective velocities in relation to the source of the sound.
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Observer A is stationary and Observer B is moving. - This situation would also result in different frequency measurements due to the Doppler effect, where the frequency might be heard higher or lower depending on the direction of motion of Observer B relative to the source.
Based on the emphasis on frequency measurements, the most relevant and correct choices would be:
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Observer A and Observer B are moving at different speeds relative to each other.
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Observer A is stationary and Observer B is moving.
Both of these situations highlight how motion can affect frequency due to the Doppler effect.
1 answer