PURPOSE: To demonstrate the effect of temperature on vibrations in a lead bell.

DESCRIPTION: The bell can be sounded at room temperature in an mpeg video. It is then cooled by placing it in a bath of liquid nitrogen, after which it is sounded at LN temperature. The difference in the tone can be ascribed to the increased crystalline structure when the bell is cooled.

SUGGESTIONS: Please be VERY CAREFUL with our bell. It was made especially for us by Clarence Bennett, physics demonstration director, emeritus, at Oakland University, Oakland, Michigan.

REFERENCES: (PIRA unknown.)

EQUIPMENT: Lead bell and container of liquid nitrogen.

SETUP TIME: 5 min.