Physics Demo Number: 036

Approximate Run Time: 5 min

States of Matter with Liquid N2 and a Banana

Demo Description

Cool one end of a banana using liquid nitrogen, leaving that end of the banana hard enough to drive a nail while the other end can still be eaten.

Scientific Principles

  • States of Matter

  • Thermal Conductivity

Equipment

  • Liquid Nitrogen

  • Styrofoam

  • Steel Container

  • Balsa wood block

  • Nail

  • Banana

Equipment Location

  • The big liquid nitrogen container is located in [D-4-1]. (Several days notice is needed to ensure available supply.)

  • Styrofoam, small steel container, balsa-wood block, and nail are in [D-4-2].

  • Banana needs to be supplied by the demonstrator.

Instructions

After the lower end of banana sits for a few minutes in liquid nitrogen, it can be used to drive the nail into the balsa- wood block. One may then peel the upper end and eat a bite off of it.

Trying to drive nail into harder wood will just shatter the frozen end of the banana.
  
Writeup created by David A. Burba
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