Final Blog Post

Ok, so when all was said and done, we think we did put in a good effort, to work on
our rocket, but we did not end up with the results that we wanted. For our final rocket
(as you can see), we added fins like we said we would. On our second day of launch,
this improved our unmodified rocket's time by 1 second (2 seconds to 3 seconds).
On the 3rd day of launch, in which we added a parachute (a plastic bag) and combined
both of our bottle together, which gave us a best time of 4.7 seconds. Not that we're bitter
or anything (yes we are), the weather on wednesday is most likely to blame for bringing
our fair time down to just 4 seconds (no modifications were made besides strengthening the
fins). Finally, on our last day of launch (the rocket used is the one shown below), we changed
out parachutes for a big garbage bag. After a few junk launches, cutting our bag into a big
rectangle gave us our final time of 5 seconds. The amount of water in the first 3 launches were approximately 500 milliliters. The amount of water in the last 2 launches were approximately 750 milliliters.

The addition that helped our rocket the most was the trash bag parachute because it caught the most wind. But on the same token, the reason we couldn't get the time needed was that it didn't  catch enough
wind. Either that, or our rocket was too heavy for it to support.

Here is a record of our development, from day 1 to the final launch day.
Both in video form and picture form.

Final Launch day

This here is another example of another day that should NOT be used for launching bottles.
But alas! We did so anyways. Here we have our last attempt to break an impossible
air time of 10 seconds. The biggest problem that our rocket seemed to have was the amount of
weight we had going for it in comparison to the amount of air being caught by the parachute. Since the parachute seemed to be unable to sustain such weight, the descent seemed all too quick, leading to the demise of our project grade for the day. We first tried cutting small holes in the trash bag I brought and tying it to our rocket, which seemed like a great idea. After a few bad launches, we decided to cut open the bag, making a huge rectangle instead. This worked just about as well as our first idea did, leaving us with our personal best of 5 seconds in the end.

Launch day 4

Ok, so you all have to admit, today was a pretty miserable day for bottle rocket launching.
Especially when you can't even get 5 seconds of air time after four tries. :(
Anyways, the video below shows our last and best attempt (4 seconds air time)
before running under cover. As for an explanation of why we didn't do so hot,
I would say that 1: Our parachute always seemed to have trouble deploying and 2: The extra
strong wind this afternoon caused the rocket to launch at an extremely funny angle.
Finally, the last huge factor that played into this would have to be the rain. It rained so hard today,
that I believe it weighted down not only our rocket, but also the parachute, possibly preventing it

from deploying as planned.

Launch day 3

So for our 3rd day of launching, we managed to pull off 4.7 seconds of air time.
What helped us today the most was our parachute. Although the parachute was rather
ghetto in a sense, (just a plastic bag), it improved our air time. Sadly, my bad camera man skills
failed to show this, but our bottle rocket glided through the air, which indeed increased our time.
As gravity pushes down on our rocket, the parachute that deploys increases air resistance by expanding it's mass. This means more glide time for us, which makes for a better time.

Launch Day 2

On today's launch, we used an unmodified and modified rocket. Our first video shows the unmodified rocket which did not launch at first. We pumped the bottle 6 times total for this launch. The total time in air was about 3 seconds. The second video shows our modified rocket launch. We attached 3 makeshift fins with duct tape. We pumped the bottle 12 times total for this launch. Our total air time on the modified launch was 4 seconds. This shows the fins could have improved our time or we had better wind conditions. It also shows that more pumps could have improved the time. For both launches we added 500 milliliters of water.

1st Launch

So, no video could be uploaded, but you should be able to see our bottle take off in this picture.... YAY!
But what makes this happen? As our helpers, Scott and Christian pump air into our bottle,
the air pressure rises, which pushes the water downwards. According to newtons third law of motion,
for every force there is an equal and opposing force. So while the water shoots down, our bottle soars up. What we screwed up on during our launch however, was our launch angle. Because we launched our bottle from a 45 degree angle....things did not go as expected.

Picture Cited: "Water Rocketry - About Bottle Rockets." Space Flight Systems Directorate / Glenn Research Center. Web. 26 Feb. 2012. <http://exploration.grc.nasa.gov/education/rocket/BottleRocket/about.htm>.

Located above is a picture we got from NASA, and the picture which we will base our rocket off of. From this website, we also learned the role each part plays in making the bottle rocket work. For our nose cone, which is supposed to help aerodynamics, we will probably make a cone out of construction paper and duct tape. We will only add the payload (parachute storage area) if needed. As for the fuel for our engine, water and air, it is under debate as to how much water will be added. As explained by: http://www.waterrocketmanual.com/how_they_work.htm, water helps propel the bottle, but only to a certain extent, and can work against the propulsion of the bottle. 

Picture cited: "How Bottle Rockets and Launchers Work." How to Make Water (Bottle) Rockets, Launchers: Complete Manual. Web. 26 Feb. 2012. <http://www.waterrocketmanual.com/how_they_work.htm>.

Based on this graph, we are probably going to aim for 30% water volume for maximum altitude. As shown in the video below, air is pumped into the bottle filled with water, which then expels the water, causing the bottle to take off. Too much water can weigh the bottle down, hindering its take off instead. 

Finally, for the fins, since they are important for stabilizing the rocket, we are thinking about wrapping cardboard in duck tape to make it more stable. 

Video cited: "The University of British Columbia." Bottle Rockets. Web. 26 Feb. 2012. <http://c21.phas.ubc.ca/article/bottle-rockets>.