Most of us may remember launching those plastic rockets that you filled with water and then pumped air inside. When you released the rocket, the compressed air inside pushed out the water and the reaction launched the rocket in the opposite direction.
We have used 1 or 2 liter pop bottles to do the same thing. Using PVC pipe we construct a stand as shown in the photo. Fill the bottle 1/3 full of water and quickly turn it upside down on the launcher. Hook up a bicycle pump and pump air into the bottle through the PVC pipe structure. The bottle will release itself from the launcher when pressure overcomes the holding force on the mouth of the bottle. The air inside the bottle forces out the water and the reaction launches the bottle in the opposite direction. It is not uncommon to reach a height of 50 feet with a 2 liter bottle.
I found this short video on the Internet the other day. It shows a young kid being hooked up to what appears to be a system of about twenty 2 liter bottles hooked together on some type of common air/plumbing assembly. The assembly is pumped up as I have described and attached to the kid's back. Somehow, all of the bottles are released simultaneously and the kid is launched out over a body of water, where he is quickly rescued.
I have run through the numbers to see if it is possible to launch the kid into the air. By my first order calculations, it would take more than 50 bottles to lift even a skinny kid off the ground, let alone that far over the water. Therefore I believe this video is fake. But it sure looks impressive. Don't you agree?
I can't tell if it's fake or not of course, so I'll take your word for it, but the commentator's voice about drove me out of my mind! Yikes!!
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