Pipes and resonant mode with a node in exact center

oregongirl

1. The problem statement, all variables and given/known data
What kind of pipe can never have a resonant mode with a node in the exact center? (choices are closed on both ends, open/closed on one end only. open on both ends) why?


2. Relevant equations
none given


3. The attempt at a solution
I think its closed on both ends because there is no where for the sound to escape, it keeps going back and forth threw the tube, but im not sure.

JRPB

I'd go with the one open on both ends. In order to achieve resonance you need a bouncing surface. In the open pipe, the perturbation will pass right through and there won't be any waves colliding and interfering, hence, no resonance.