Water Bottle Rockets !!!!

Capri and I made our rocket today out of some simple materials. We used some posterboard, duct tape, string, an extra cut up bottle top, rocks, a trash bag, and more tape. I made the fins out of posterboard, and shaped them to look like surfboard skegs. I was just experimenting with the shape of the fins, trying out something a little different than the generic triangular shape. I wasn't sure how the shape would affect the bottle, but I made sure the fins stayed relatively small and closer to the bottom of the rocket, so it would be stable during the launch. I also taped up the fins with clear tape to make sure the water wouldn't destroy them after one or two launches. I taped the fins onto the bottle (an equal distance away from each other) with duct tape to make sure they would stay attached to the bottle.

Capri then made the parachute out of a trashbag, and we taped strung some string through it and taped it onto the top of the bottle. We then made a weighted top out of a cut out top of another bottle. Inside the top, we taped some rocks and string to add about 50 grams to the top, so the bottle would not tip.
We used about 1 2/3 liters of water to launch for the first two trials. The first trial worked out really well, but the parachute didn't deploy, but it did stay in the air for about 5 seconds!