No one should be subjected to the stupidity of Physics. Especially if they are busy people...
I know that Miss Maura and Miss Katie both have to suffer through Ms. Chase and her projects. So these are three web pages I found that might be of some help. The last one is probably the best.
http://materials.npl.co.uk/waterrockets/rockets2.html http://www.owu.edu/~mggrote/phys98/le_12.html http://ourworld.compuserve.com/homepages/pagrosse/h2orocketsi.htm