Excited by the in class experiments you put two speakers in your living room 80cm apart producing a sound of 750Hz. 4.0 m away you place a microphone right on the centerline between the speakers. Will the microphone detect a loud sound or a soft on at this point (relatively to the space around)?
To determine whether the microphone will detect a loud or soft sound at the given location, we need to understand the concept of sound interference. When two speakers are placed close to each other and emitting the same frequency, they create what is known as an interference pattern.
In this scenario, the speakers are producing a sound wave with a frequency of 750Hz, and they are placed 80cm apart. When two speakers are close together like this, they create an effect called constructive interference in some regions and destructive interference in others.
Constructive interference occurs when the sound waves from the two speakers meet and combine in phase, resulting in a stronger and louder sound. In the region where the sound waves combine constructively, we expect the microphone to detect a loud sound.
Destructive interference, on the other hand, occurs when the sound waves from the two speakers meet and combine out of phase, resulting in a cancellation or reduction of sound intensity. In the region where the sound waves combine destructively, we expect the microphone to detect a softer sound.
To determine whether the microphone will detect a loud or soft sound at the given location, we need to identify the interference pattern created by the two speakers. Since the microphone is placed exactly at the centerline between the speakers, it will experience the maximum constructive interference.
Therefore, the microphone will detect a loud sound at this point relative to the surrounding space.