singing wine glasses

[rennie]

Thanks for helping!

[deleted-71588]

So, how am I supposed to support my hypothesis with lack of well-argued physics theory?

You go back to definitions. What is the simplest definition of density? Density is just mass (or weight) divided by volume. Did you measure the volume and weight of each of the liquid samples used? If not, then your experimental proceedure was flawed and you need to modify your proceedures and repeat your tests.

Also, does sound travel faster in a dense liquid than a less dense one? I'm thinking of the equation f= velocity/wavelength. Since the speed of sound changes depending on the medium, will this equation be a supporting formula to my hypothesis?

I see no direct connection between sound propagation in various medium with your hypothesis associated with a resonant frequency of an object.

The resonant frequency of a wine glass filled with air will depend on a lot of geometric factors. Because of this, you should be using the same wine glass for all your experiments. A matched set of wine glasses maybe close enough; however, you would have to run a lot of experiments to just prove that. The simplest approach is to use the same wine glass.