If the sound waves detected by the dector is the same as the frequency of the source, what can we conclude about the motion of the source and detector?
If the sound waves detected by the detector have the same frequency as the source, we can conclude that the motion of the source and the detector is either stationary or moving with the same velocity towards or away from each other.
To understand this, let's consider the effect of motion on the frequency of sound waves. The frequency of a sound wave is defined as the number of cycles it completes in one second, expressed in hertz (Hz). When a source of sound waves approaches an observer, the waves get compressed (higher frequency) due to the relative motion. This phenomenon is known as the Doppler effect. Conversely, if the source moves away, the waves get stretched (lower frequency).
Now, if the sound waves detected by the detector have the same frequency as the source, it means that no change in frequency occurred during the propagation of the waves. This can happen in two scenarios:
1. Stationary Source and Detector: If both the source and detector are stationary, there is no relative motion between them. As a result, the sound waves emitted by the source reach the detector with the same frequency as they were emitted.
2. Source and Detector Moving with Same Velocity: If both the source and detector are in motion, but their velocities are equal and in the same direction, their relative motion is zero. In this case, again, no change in frequency occurs because there is no relative motion between the source and detector.
Therefore, we can conclude that if the sound waves detected by the detector have the same frequency as the source, either the source and the detector are stationary or they are moving with the same velocity towards or away from each other.