Physics of Rocket

In the making of our rocket we discovered in order to make a bottle rocket you need 4 things: Two 2 Liter soda bottles this will be your rocket and your nose cone area, You will need to make fins out of any hard material we used cardboard nd CD's, number three! H2O you need water to power your rocket so it will launch into the sky and orbit! (or crash and kill your egg..) and finally.. Air Compression.  Without Air Compression your 2 liter bottle rocket is just a sad excuse for a cool looking soda bottle.  Newtons first Law of motion states that An object at rest will stay at rest until an outside force acts on it.  This outside force is the Water and Compressed Air, they act like Engine fuel.  The other side of Newtons First law is that an object in motion will stay in motion until an outside force acts upon it.  The outside force in this scenario is Gravity and Air resistance, in order to defeat air resistance on will need Fins attached to ones rocket providing aerodynamic procedure of air passing by the rocket (in other words to push the air away from the denser parts of the rocket.  As for gravity we used gravity to our advantage by making a parachute because of the gravity and air resistance we have on earth a parichute is the only safe way to fall from high distances and not die.