3D40.?? Coffee Cup Resonance

PURPOSE: To demonstrate resonance in a common solid

DESCRIPTION: Even common objects demonstrate the effects of resonance. Hold a coffee cup carefully on the bottom with the handle pointing towards your body. Visualizing the cup from the top (open end) with the handle at "6", there is a node or antinode when the rim of the cup is struck (lightly) every 1/8 of the way around the cup from this point.

The handle slows down the waves of vibration in the cup, so it will be a node and have a smaller frequency (lower pitch). The other nodes will be at the points "9:00", "12:00", and "3:00". The antinodes are located at "1:30", "4:30", "7:30", and "10:30" and will have slightly higher pitch.

SETUP TIME: Minimal

COMPONENT LIST:

    


  1.  Coffee Cup			Bring your own or borrow one


  2.  Spoon			"

SUGGESTIONS: The classroom will have to be fairly quiet for everyone to hear this. Practice ahead of time to make sure you can find the nodes/antinodes!

REFERENCES: PIRA 3D40.??

OTHER NOTES: