Team Awesome’s Awesome Cannon of Awesomeness
and the effects of the amount of fuel combustion on the range of the highly
volatile projectile which travels at a high velocity
Zack Edwards
Albin Ljunghusen
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Background Information
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The cannon was invented in China as an artillery weapon. It evolved from the
“fire-lance” which was a spear with a tubular structure on the end that was used
as a flamethrower. The first documented use of a cannon on a battlefield was in
1132.
The modern cannon is used on tanks and battleships. It has gone from taking200
men to operate (Constantinople) to being an automatic firing device that can be
maneuvered by a single human being.
A cannon usually exists of a chamber to put the fuel in, a barrel to guide the
projectile the right way and to let it accelerate, and some means to ignite the
fuel.
Statement of the Problem
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The purpose of our experiment is to find a relationship between the amount of
fuel used and the distance (range) our projectile will travel. The amount of
fuel that we will use will range from 4ml – 12ml in increments of 2ml.
Review of Literature
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From watching videos on YouTube we learned how to build the cannon. We limited
our research to how far the projectile will travel depending on how much fuel we
use. Our first problem was how to know how much fuel we put in since we planned
on using hairspray as a propellant.
The physics behind a fired projectile is very complex so this formula is only
correct if we neglect the wind resistance and the target is at the same
elevation as the cannon itself.
Range = (Sin(2Θ) * Initial Velocity2)/g
To get valid data points we will have to keep the angle of our firearm and the
mass and shape of our projectile remain constant.
Our cannon has a 2ft of 3”PVC pipe as chamber and 4ft of 2” PVC pipe as barrel.
To ignite the fuel we charge up a capacitator and close the circuit inside of
the chamber; this creates a spark that lights the fuel.
Hypothesis
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Logically if we use more fuel, there will be a larger explosion, which in turn
will exert more force on our loaded projectile, which in turn will increase the
distance of which the object travels and the initial velocity. Distance will be
measured in yards and then converted to meters. Fuel will be measured in ml.
Initial velocity will be calculated in m/s.
Procedure
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Since we wanted a projectile that would act the same in every shot we took a
tennis ball and wrapped it in aluminum foil. We then wrapped it in painters tape
and painted it with glow in the dark paint so that we could find it if we fired
our cannon in the dark. To make it easy to measure how far our projectile
traveled we did our measurements on the school turf. We placed our cannon on a
step ladder at a 30 degree angle with a piece of tape on the barrel for a marker
so we can recreate the launch angle.
Results and data
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RANGE
|
Methanol (ml) |
4 |
6 |
8 |
10 |
12 |
|
Shot 1 (m) |
33.83 |
46.63 |
74.98 |
84.12 |
93.27 |
|
Shot 2 |
31.08 |
42.98 |
71.32 |
86.87 |
87.78 |
|
Shot 3 |
30.17 |
44.81 |
69.49 |
90.53 |
91.44 |
|
Shot 4 |
28.34 |
42.98 |
70.41 |
87.78 |
86.87 |
INITIAL VELOCITY
|
Amount of fuel (ml) |
4 |
6 |
8 |
10 |
12 |
|
Initial Velocity (m/s) |
18.69 |
22.43 |
28.46 |
31.43 |
31.89 |
Data file
Conclusion
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One of the first things that we noticed when we looked at our data was that for
every shot we fired the projectile seemed to travel a shorter distance even
though we used the same amount of fuel. We believe that this is because we
didn’t wipe out the inside of the chamber enough, thus leaving water and other
wetness inside the combustion chamber. We also found that when using higher
amounts of our fuel the ranges and initial velocities started to level off
showing us that there is a prime amount of this type of fuel for vaporization.
Another problem that occurred is that we launched on the turf field where the
yards are marked, and we didn’t have a measuring tape so we had to estimate as
best we could when it landed in between the markings.
Bibliography
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J. B. Calvert. Cannons and Gunpowder [online] January 2000.
http://mysite.du.edu/~jcalvert/tech/cannon.htm
David Wallechinsky & Irving Wallace. Military and War Weapons the Cannon.
[online] 1975 - 1981
http://www.trivia-library.com/b/military-and-war-weapons-the-cannon.htm
Author Unknown. Artillery Applications. [online] 12/01/99
http://www.evac.ou.edu/jmpbac/appl.html
Author Unknown. Potato Cannon Workshop. [online] 1999
http://potatocannon.nodice.org/
Multiple. Potato Cannon Improvements. [online] 2000
http://www.geocities.com/Yosemite/Rapids/1489/improve.html#16
Chris Murray. Lessons on Cannon Mechanics. [speech] 2007
Related sites
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This is a site run by Joel D. Surprise. It gives you info on how to build your own spudgun. It has info on the pros and cons of different materials. It also has pictures of his wife shooting spudguns in Iraq, it's awesome.
How to make a spud gun shows the mechanics of the potato gun. It shows the gun taken apart which is very helpful because it acts as a blue print. It also has material lists and a public forum where people can make comments on improvements and other tips.
Beginner's Spud Gun is another site where is shows how to make an awesome cannon! It gives a little information on the "weapons" themselves which I deemed to be helpful.
This was one of the best sites in my opinion. It takes you step by step and gives you multiple ways to build a cannon. It also lists the risks and dangers to using such a device.
This site is basically just a forum where people from all over the place discuss potato guns. This was very helpful because it gave insight to what people thought about the different designs. People also listed the flaws and things that needed improvements on the conventional designs.
Albin Ljunghusen Period A3
Zachary Edwards Period A1