Sound Waves and Interference: Understanding Loud and Quiet Spots

Where is Susan standing in relation to the two speakers?

If Susan stands 19.5 m from one speaker, is she standing at a quiet spot or a loud spot?

Answer

She will be standing at a loud spot.

To determine if Susan is standing at a quiet spot or a loud spot, we need to consider the difference in the path of the sound waves reaching her from the two speakers. When Susan stands 19.5 m from one speaker, the distance to the other speaker is 22.5 m. The difference in the path lengths is 3.0 m, which corresponds to one wavelength of the sound wave. This results in constructive interference, creating a loud spot where Susan is standing.

Sound waves travel through mediums such as solids, liquids, and gases. Understanding the concept of interference helps explain the variation in loudness at different points in the room where the speakers are placed.