Mr Murray's Physics Homework

How to Make an Easy 2-Liter Bottle Water Rocket I'm going to show you the absolute easiest way to make a water rocket, using only duct tape. The following rocket held up to 90 PSI of air and was launched five times. The duct tape never failed, including on the fins. The fins on other rockets attached with adhesives (like epoxy) broke off. We reattached them with, of course, duct tape! (The duct tape is flexible. Epoxy is rigid.) Materials: 2 empty two liter bottles (good time for mentos and Diet Coke!) (Note: not all bottle fit the launcher! The following do: Coke Products [Diet Coke, Sprite]) presentation board, strong styrofoam, or very strong cardboard (not construction paper). Dirt or other material for weight (rice, beans, rocks...) Duct Tape! Whatever you want to decorate it with.
Cut the end off of one of the two liter bottles. Shove this piece into the top part of the bottle.
		This makes a chamber to hold some weight (dirt or something). You will want to glue or tape it into the bottle. The weights can be inserted thru the opening and closed with the lid.
Put the other bottle into the first, as shown and duct tape the two bottles together. This second bottle will be your engine so DON'T DAMAGE IT! DO NOT get dirt, rocks, or sand into the engine bottle. It could damage the launcher. Cut 3 or 4 small fins and attach them with duct tape.
		Here's a close up of the fin and its beautiful duct tape job. Notice how far away from the the fin is - that's important! If the fin goes too far down it will interfere with the launcher and we'll have to trim them to fit.
Here's an example of a finished (and used) rocket. This one didn't use duct tape. You can decorate it with colored duct tape, paint, or whatever. Get creative!