PURPOSE: To show that helium gas contracts when it is cooled.
DESCRIPTION: A helium balloon which is cooled by a liquid nitrogen bath becomes heavier than air. When the balloon is removed from the liquid nitrogen it warms up, expands, and floats away.
SUGGESTIONS:
REFERENCES: (PIRA 4E10.20)
EQUIPMENT: Helium balloon, liquid nitrogen.
SETUP TIME: None.
 |  |  |  | 
|