What are some fun experiments with liquid nitrogen?

[gijsbert2002]

Hello, I'm with a group called RINO (would give you a webiste, but don't have one yet). In Holland we go to schools to do shows with liquid nitrogen. At the moment we're trying to improve our show, so we're thinking about new experiments. I was hoping some of you might have a great suggestion.

Right now we're doing several things,
- change of sound when something is cooled down,
- what happens to fruits when they are cooled down (they become hard, some can shatter )
-make small explosive sounds when you put some water in a cup with LN2
-things shrink when they are coold down
-and as a new experiment we can create small amounts of liquid oxygen and use that to relight a match that has gone out but still glows.

Thanks in advance for any suggestions, Gijs.

whoops, this might just be more of a general physics subject.

 

[FredGarvin]

When I did similar physics demos in college for local grade schools, one that we did involved a small magnet that we cooled with LN2. It would levitate off of it's base as long as it was cold enough. I can't remember exactly what material the magnet was though.

 

[brewnog]

Bit of liquid N2 in a coke bottle, cap on, then wait a few seconds...

Oh how the teachers didn't see the funny side.

 

[gijsbert2002]

Bit of liquid N2 in a coke bottle, cap on, then wait a few seconds...

Oh how the teachers didn't see the funny side.
Today 06:31 PM

Normally, we try not to kill the people we're trying to give an interest in physics, but if you insist
We keep very high standards of safety including special trainings in safety and extensive tests on everything we do, so we're looking for fun, but safe or "can be made safe" experiments. For example, the liquid O2 experiment is in general not safe, but because we're using really small amounts, working on a small place and having no contact with anything inflammable, it's safe.

When I did similar physics demos in college for local grade schools, one that we did involved a small magnet that we cooled with LN2. It would levitate off of it's base as long as it was cold enough. I can't remember exactly what material the magnet was though.

What floor was the magnet laying on?
We use magnets only to hover above a superconductor.

 

[FredGarvin]

What floor was the magnet laying on?
We use magnets only to hover above a superconductor.

Same thing here. It sounds like you are doing the same thing.

 

[gijsbert2002]

Does anyone have any more new ideas?

 

[xJuggleboy]

Bit of liquid N2 in a coke bottle, cap on, then wait a few seconds...

Well you can make this a bit safer by using a cork rather than the cap...

Hold the cork on for a few seconds and let go... Should go flying across the room or hit the ceiling...

I also had a science teacher drop a I've goldfish in N2 pul it out and drop it in some water and it will come back to life.

 

[gijsbert2002]

We already do the cork trick. It puts dents in the ceilings of classrooms and can reach more than 15 meters high. That's one of the more fun parts of the show.