PURPOSE: To demonstrate how a normally elastic material at room temperature becomes rigid at very low temperatures.

DESCRIPTION: Very carefully drop a racquet ball into liquid nitrogen, then when it stops bubbling throw it against a wall or floor to break it up into pieces.

SUGGESTIONS: Handle the cold racquet ball with tongs or gloves. Wear approved eye protection for safety. Also do not throw it in the direction of the students

EQUIPMENT: Dewar with liquid nitrogen, racquet ball, tongs, gloves and safety glasses.

SETUP TIME: 50 min.

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