Straw Rockets

Hey Everyone!
So the past couple of days I have been working on straw rockets. The matterials used were: clay,straws (different size straws), a liter bottle, paper, and scissors. You take the straw and put into the liter bottle and seal the bottle off with the clay, make a rocket with the other straw and seal off the end with the rest of the clay. Make three different types of rockets and shoot them off. When you are done with shooting each of the rockets off, record the distance and get the average. When i shot my rockets off, the ones with to much clay at the top were top heavy and took a nose dive. The one that didn't went much farther. Good Luck! :)