The Bottle Rocket

1)Q Focus
Does more fuel automatically make the rocket go farther?
---------- I learned from one of my failed rockets that if the fuel is heavier than the front of the rocket the flight will spin out of control. It is important to have the weight of the rocket and the weight of the fuel to be similar. In my case if i had used less fuel my rocket would have gone farther.
What type of fins will help the rocket go farther?
---------- I learned that larger fins work better than smaller fins to have a straight flight trajectory because i observed that rockets with rectangular finned rockets didn't go as far as those with triangular rockets. Also triangular fins, work best, and 30-60-90 triangles work best. Our working rocket had larger fins than our failed rocket.
What is the importance of the cone of the end of the rocket?
---------- The cone provides weight to balance out the rocket fuel and it prevents the rocket from hitting the ground right where the egg is. Both circular styrofoam tops and styrofoam cones worked well. However, from my observation of the other rockets the one with cones on the front went the farthest.
2)Making of the Rocket
-materials: two bottles, duct tape, styrofoam ball, cotton balls, cereal box, small container
-we made the fins by cutting up the cereal box into 4 fins and ductaping them to the rocket
-we cut the styrofoam ball in half to make a dome top for our rocket and we shaved down the bottle and the ball to fit them on top of each other
-we reinforced everything with duct ape

3) Physics of Rocket

I) The pressure inside the bottle, 80 psi, is a lot higher than the air outside, and this creates potential energy that will be used during the launch. Because the rocket is in its resting position the net force acted on it is 0. However there is force exerted on the rocket by gravity, the pin (that holds the rocket to the pad) and the bars that hold the rocket in place.
II)The rocket is propelled into the air as the pressure and water leave it. In this phase the rocket loses potential energy and gains kinetic energy. The direction of the net force of the rocket is forward because the rocket is moving forward and up. The forces acting upon the rocket now are air, the expelling water and gravity.
III) The rocket is now out of fuel and the direction of the net force is towards the earth. The forces that are  acting on the rocket are now only air and gravity. The rocket is still gaining downward speed as it plummets to the earth because all of its potential energy is transforming into kinetic energy.
IV) The rocket has now made contact with the ground, and the kinetic energy is now thermal. The pressure inside the rocket is now the same as outside the rocket and the net force is again 0. The forces acting on the rocket are now gravity, the ground and air

4) Inside the rocket I used cotton balls and a styrofoam container to protect my egg. An additional means of protection was the parabolic styrofoam dome which absorbed a lot of the impact from the fall, thereby protecting my egg. The Styrofoam distributes the force onto a larger area of the rocket and decreases the likelihood of the egg cracking.The cotton balls increase the amount of time it takes for the egg to absorb the momentum.
5) Results
-My rocket went 60 meters on a 40 degree angle with 900 mL and my egg survived.

The rocket was heavy on top so we chose a higher amount of water to help give it more propulsion force so that it would go the necessary distant. We chose a 40 degree angle to prevent the rocket from landing straight down.

The second rocket only went 20 meters on a 40 degree angle with 900 mL and a surviving egg. This was just a back up launch so we didn't put as much effort into the rocket. The amount of water was to great for the light rocket, so the rocket spun out of control. I think that if we had used a lesser amount of fuel the rocket would have worked.

6) What I learned

-I learned how the laws of physics are applied to a rocket. I also learned how aerodynamics play a large role in how far a rocket goes. I didn't predict how difficult it would be to protect the egg, and this project broadened my perspective of the power of an impact. I now appreciate more how planes and rockets work, because it is really difficult to protect objects that are moving at such a high speed. Also after attempting to draw the diagram on sketch book I appreciate your skill at writing on the computer more.