marshmallow cannon

November 28, 2013

Episode 2

Pressure differences can create large forces.  A great example is an air cannon.  It’s the same idea as a potato gun but instead of using something explosive to create the high pressure I’m using a bike pump.  Here’s the video:


A few details

I’ve been using this particular marshmallow cannon for about ten years now.  However I went through lot of cheaper bike pumps in the early years.  Most of the under $20 pumps just can’t handle the pressure for very long.  I finally bought a beefier pump with a gauge and it has been awesome.  I also bought one for home.  If you’re interested here is the link an amazon:
Topeak Joe Blow Sport II Floor Pump

The slow motion video I took with my camera is kinda fun.  I’m not a pro at using it yet, but I have learned that it needs to be well lit.  The lighting is not great in my classroom, but it worked OK.  The shot with the pepsi can was using 240 fps (frames per second) and the energy drink can was 480 fps.  It’s obvious at the 480 level that the video is more grainy, but it does freeze the motion better.  Here’s the link to the camera:
Casio High Speed Exilim Ex-zr200 Digital Camera Black Ex-zr200bk

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