What size bottle makes the best Model Rocket

For our science fair progect our question was What sized pop bottle  (modle rocke) works the best (2L or  500ml ) and how much water do you  need.

     Hypothisis
We thought the two liter pop bottle wouled work the best with it a quarter full of water.We think that because it can hold the most pressuer.

Things we needed!!

• 2l plastic pop bottle
• Air Pump
• Cork
• Air Needle
• 500ml Plastic Pop Bottle

Procedure
steps
1. we put a hole in a cork
2. we put the air needle into the hole in the cork then, we put the air needle on a bike pump
3. we inserted the cork into the mouth of a bottle
4. then we pumped it up untill there was enough pressure for the cork to pop out and the bottle to shoot off
Fins and a nose cone are optional but inprove stability and aerodynamics

Reasults

No water
2L 20meters
500ML 16meters

Quarter full
2L 23meters
500ML 17meters

Half full
2L 21meters
500ML 13meters

Three quarters full
2L 6meters
500ML 12meters

Totally filled
2L 20cm
500ML 60cm