- The guitar string
- The air inside the guitar
- The air surrounding the guitar
- The ground beneath the musician
(a) & (b)
This is College Physics Answers with Shaun Dychko. A standing wave will exist on the guitar string for sure and it will also exist inside the guitar. And that's the reason for having a body on the guitar. Having this air that is trapped inside a vessel of the guitar body, it provides a resonator. The air is running the guitar will not resonate because in order for resonates to happen the wave has to bounce off of something, and there is nothing to bounce off of outside of the guitar. And it will not resonate the ground underneath the musician very likely because when it bounces off the ground, it is too diffuse and there is no possibility for interference with the next wave that is coming in, because standing waves occurs because of interference between a reflection and the incident waves. Anyway, the answer is a and b.