Physics EE - water bottle rocket

[roope]

I'm a bit stuck on narrowing down my topic to a specific research question. Currently I have a few ideas on optimizing the mass of water, or investigating air resistance, but they all seem too trivial. I also had a small look at a steam rocket, but that seems it may take up a bit too much of my time to build.

Thanks in advance for the help.

[lolipop_choc]

well, I don't know if this helps but I'm going to type it anyway.

I'm doing physics EE, too. I'm doing stuff about the solar energy and how to use it to boil a water. I still cannot figure out how to do it but I think it is quite interesting (at least for me). So , this might be an idea for you if you haven't chosen the topic yet or want to try something else.

Hope this helps

[Procrastination]

Try changing the nozzle transverse area for your independent variable to see how propulsion may vary in relation with the size of the radius. You can come up with a pretty interesting EE with this, considering other variables which might affect the water bottle rocket such as air resistance.