Why does a wine glass make a high pitched noise when i rub my finger along the rim?

Answer 1

Because your finger alternatively holds and slip at high frequency while rubing on the hedge, like "bouncing" on the hedge of the glass. Those quick and tiny bounces make the thin and frail glass vibrating at a frequency high enough to produce an audible sound (several hundreds to several thousands of hertz of frequency).
The shape of the glass acts as resounding case, exactly as a bell does, and thus it amplifies the vibration to the point that it is audible at distance. Then the volume of the glass exerts influence upon both frequency (that is to say the note) and intensity (decibels).

In sum, the trick consists of making a thin piece of glass entering into vibration.

Answer 2

the form of the glass. assorted issues in an environment effect sound. think of of it as like certainly one of those previous microphone toys that made you sound extraordinary. Or do an expirament by filling a common cup with 3/4 and a million/2 water, and tapping it with a spoon.

Answer 3

The ridges in your finger-print are making vibrations.
The glass will vibrate at different frequency with water in it.

Answer 4

everything makes that sound when u do that if you can get it to vibrate
. its only on some surfaces your ears can hear the pitch