Physics at the University of Virginia
Academics People Research Announcements Facilities Adminstration Home Updates

Return to Demo Lab Homepage

Al Tobias (wat4y) - Office: Gibson S123 & Physics 218, (434) 924-0538

Physics Demo Manual

Demonstrations are cataloged according to PIRA Bibliography


Due to Physics Building renovations, the lead time to set up demo requests has increased due to the need to transport equipment across campus. Please be kind and let me know well ahead of time what you need.

Choose a Topic or Enter a keyword to search:
I cannot find what I want!

You have selected the following Demos:
  • None Selected

Choose a subtopic:
(Clicking a green button will add that demo to your list)
 Thermal Properties Of Matter
 Heat And The First Law
 Change Of State
 Ice Bomb (expansion of water upon freezing)
 Regelation in Ice
  video  - Thermocouple in Ice
  video  - Boiling by Cooling
  video  - Boiling by Reducing Pressure
  video  - Crush the Soda Can
 Sling Psychrometer (Relative Humidity)
 Phase Change in Iron
 Kinetic Theory
 Gas Law
 Entropy And The Second Law

Ice Bomb (expansion of water upon freezing)


To show that water expands upon freezing, and the great forces that are involved.


Fill cylinder with distilled/deionized water. Place red plastic plug on top to seal water in being careful not to entrap any air. Use the appropriate number of spacers (usually two) to make the cast iron bolt fit tightly thru holes (the tighter the better).

Fill plastic container with LN2 and place Ice Bomb apparatus in standing up. It will take less than half a minute for the bolt to break. You will hear crackling noises as the ice expands and at the end a significant expansion will be visible.

The Ice Bomb is made by 3B Scientific. The manual is available here.


  • Distilled/deionized water is used since it will not have any gas dissolved in it like tap water does.
  • Do not center a "new" cast iron bolt. Allow one end to stick out the side less than 1 cm so that after the bolt breaks, there is enough bolt length left to use for a second time.