A hypothesis is something that you believe will happen before you test it in an experiment. We wrote hypotheses based on the experiment on building a rocket. We guessed what would happen if we tied balloons to a straw that was tied on a string and then let go. Our general hypothesis was, If you tape a balloon to a straw that is tied on a string, then depending on the amount of air in the balloon will tell you how far the balloon will go. Check out our pictures and video.