Science Buddies: "Ask an Expert"

How does air pressure make a rocket move up?

How much water should I use? What percent? We are using a 2L bottle?

What size of fins are recommended?


Does the length of the rocket matter? Should it be longer or shorter?

Hi MrBremmer,
I am guessing you are working on this experiment?
https://www.sciencebuddies.org/science- ... background

The background section have a really nice description of how air pressure is part (how fast) of the "reaction engine" of the rocket. In regards to how much water you should use, the procedure section calls for 700ml.
https://www.sciencebuddies.org/science- ... #procedure

Finally, in regards to fins, please take a look at this link:
http://www.water-rockets.com/article.pl?121,0

Good Luck and please post again if you have any more questions!
Willey