Does a object always ring at resonant frequency? I'm trying to find the resonant frequency of glass panes and how the resonant frequency is affected by the thickness of the glass pane. I set up the glass pane with the ends of the glass pane fixed. (I want to pass a first harmonic wave through the glass)
I was thinking that I could tap the glass and hear the frequency the glass rings at (measured using oscilloscope)
Would this be a correct way of measuring the resonant frequency?
(I'm doing this at home, so I understand there is going to be a decent amount of error. I just want find out a relationship between the two variables)
 A: Initially, not all objects when vibrated at their resonance frequency creates sounds that are detectable by human ears so, if your glass panes have higher resonance frequency you may not hear anything even if you can continue correctly.Your method will be quite challenging because any defect and antisymmetry in the tapping of your fingers causes a wrong tone because the force changes drastically. To overcome that problem you need a high quality crystal glass that generally has resonance frequency about the range of human hearing. In addition, observing the outcome on an oscilloscope will not help enough with your tapping method because you need a calibration check or some sort of test output at the resonance frequency you may use crystal glass otherwise different low quality glass will give you bad results. As a suggestion, you may use piezoelectric transducer. Which can be used both as a source of vibration and as a detector. You simply attach transducer to glass and using a driver circuit for it you can find the resonance frequency of glass.
