posted by Erica--help! .
Resonance of sound waves can be produced within an aluminum rod by holding the rod at its midpoint and stroking it with an alcohol-saturated paper towel. In this resonance mode, the middle of the rod is a node while the ends are antinodes; no other nodes or antinodes are present. What is the frequency of the resonance if the rod is 1.30 m long?
I never found it necessary to soak the towels.
the rod is 1/2 wavelength, so wavelength=2.6m