Which situations might cause two observers (A and B) to measure different frequencies for the same vibrating object? Select the two correct answers. (2 points)
Responses
Observer A and Observer B are stationary but at different distances from the vibrating object.
Observer A and Observer B are stationary but at different distances from the vibrating object.
Observer A is stationary and Observer B is moving.
Observer A is stationary and Observer B is moving.
Observer A and Observer B are moving at different speeds relative to each other.
Observer A and Observer B are moving at different speeds relative to each other.
Observer A and Observer B are both stationary and at the same distance from the object.
Observer A and Observer B are stationary but at different distances from the vibrating object.
Observer A and Observer B are moving at different speeds relative to each other.
The two correct answers are:
1. Observer A and Observer B are stationary but at different distances from the vibrating object.
2. Observer A and Observer B are moving at different speeds relative to each other.
The two situations that might cause two observers (A and B) to measure different frequencies for the same vibrating object are:
1. Observer A and Observer B are stationary but at different distances from the vibrating object.
When an object vibrates, it emits sound waves that propagate through the medium. The frequency of the sound wave determines the pitch or perceived frequency of the sound. If Observer A and Observer B are at different distances from the vibrating object, they will experience different levels of intensity or loudness of the sound wave. This is because the intensity of the sound wave decreases with distance. As a result, the perceived frequency of the sound wave will be different for both observers.
2. Observer A is stationary and Observer B is moving.
When an observer is moving relative to a sound source, they experience a phenomenon called the Doppler effect. The Doppler effect causes a perceived change in frequency based on the relative motion between the source and observer. If Observer B is moving towards the vibrating object, they will perceive a higher frequency than Observer A because the sound waves will be compressed due to the relative motion. On the other hand, if Observer B is moving away from the vibrating object, they will perceive a lower frequency than Observer A because the sound waves will be stretched or elongated due to the relative motion.
Therefore, the correct answers are:
1. Observer A and Observer B are stationary but at different distances from the vibrating object.
2. Observer A is stationary and Observer B is moving.