New Thing #277--Project Propel

A couple of weeks ago one of my students was playing with a water bottle. I watched him twist the empty water bottle (with the cap on), then loosen the cap so it shot across the room. Although he did it when he was supposed to be working I had to come down hard on him, but I was secretly fascinated. Today I tried it myself and I shot the lid off a water bottle.

There was a half-empty bottle of water that had been sitting on a shelf in the basement for quite some time; I decided to have a little fun with it before it got recycled. I didn't want to waste the extra water, so I dumped it onto one of the plants on the deck, then put the lid back on the bottle. I started pinching the area right under the label, then twisted it tightly. This was harder than it looked. I had a hard time getting my hands around the bottle and keeping it twisted. (The cap shoots off because of the air pressure you create by twisting the bottom of the bottle. The more you pinch, the harder and farther the cap will shoot.)

This is a great explanation of the process:

I sat in a chair on the front porch and pointed the bottle towards the yard. The cap was supposed to fly off with a lot of pressure, so I didn't want it to hit anything; I could see how the cap could cause some serious injury when it flew. Unfortunately, my cap didn't fly too far, probably because I wasn't able to twist it as tightly as it should have been. It crossed the sidewalk and ended up on the grass. I got the tape measure for an official measurement-- it was about eight feet away.

Since you can only use a bottle once, when I was done I put it in the recycling bin. However, I may have to try again next time I have an empty bottle of soda or water.