container of liquid nitrogen, bananas, nails and boards
container of liquid nitrogen, bananas, nails and boards
dewar flask, mercury container, plastic beaker, paper cup, stand
dewar flask, mercury container, plastic beaker, stand

 

Code Number: 4A40.20

Demo Title: Liquid Nitrogen - Banana and Mercury Hammer

Condition: Good

Principle: Material Properties at Low Temperature

Area of Study: Chemistry and Physics

Equipment: 

Liquid Nitrogen, Dewars, Plastic Beakers, Mercury, Paper Cup, Tongs, Bananas, Nails and Boards.

Procedure:

See also: 4A40.20 in Chemistry and Physics of Everyday Experience

Arrange ahead of time to get liquid nitrogen from either Biochem Stores . Typically it takes about 4 liters for each classroom demonstration.  Freeze a banana and you can drive nails with it.  The fibrous nature of the banana keeps it from breaking apart easily.  

Directions for the Mercury Hammer can be found in the files or the hardcopy 4A40.20 entry.  

The temperature of liquid nitrogen should be a -196oC or approximately 77o K.

References:

  • Hk-7, 8:  Freier and Anderson, A Demonstration Handbook for Physics.
  • H-078:  "Objects in Liquid Nitrogen",  DICK and RAE Physics Demo Notebook.
  • Mike Walker, "Cold, Hard Facts", Popular Science, June 2009, p. 74.
  • Gordon McComb,  Lasers, Ray Guns, & Light Cannons - Projects from the Wizard's Workbench, pp. 28.
4A40.20 - Liquid Nitrogen - Banana