- #1
Pereskia
- 15
- 2
Two of my pupils in secondary high school is doing a project on the sound generated by striking glass bottles drumsticks.
They fill the bottle partially with water and strike the bottle with a drumstick and record the sound.
Preliminary results:
As long as the water level is in the cylindrical part of the bottle the frequency gets lower with more water. (Rules out Helmholtz and standing wave in the air above)
Filling water over the cylindrical part does not change frequency any more.
The frequency does not depend on where the bottle is hit. The resonance seems however better if the bottle is stuck below water level.
Any ideas what the resonator is. Is there a standing wave in the water? Or is the water causing a standing wave in the glass below the water level?
They fill the bottle partially with water and strike the bottle with a drumstick and record the sound.
Preliminary results:
As long as the water level is in the cylindrical part of the bottle the frequency gets lower with more water. (Rules out Helmholtz and standing wave in the air above)
Filling water over the cylindrical part does not change frequency any more.
The frequency does not depend on where the bottle is hit. The resonance seems however better if the bottle is stuck below water level.
Any ideas what the resonator is. Is there a standing wave in the water? Or is the water causing a standing wave in the glass below the water level?