Want to know a secret? Well too bad. You don't get to know a secret. Why not you may ask? I'll tell you why.
It's because what I'm about to tell you isn't a secret. It is know by a great many people, and you are soon to become one of them. Now that we have that out of the way, it is time for me to inform you on how this cannon was designed and constructed, and some of the reasoning behind this.
The basic principles here are to minimize the volume of the combustion chamber in order to reduce the volume possible for the gasses of the propellant combustion products to expand into. This will increase the pressure exerted by the propellant gasses and thus launch the projectile a further distance.
As the volume of a fixed quantity of gas contracts, the pressure increases, as demonstareted in Boyle's gas law. Armed with this knowledge, I was able to deduce that a smaller combustion chamber would result in a more effective cannon.
The cannon was constructed by shearing off the end of a tennis-ball cannister to about half its orignial length, and then taping the resulting product at a 45 degree angle to another, horizontal tennis-ball cannister.
A hole was bored at the base of the combustion chamber to allow for ingnition of the fuel mixture. A 45 degree angle was chosen because this is the optimum angle for launching a projectile in order to achieve the greatest horizontal distance.
Wow I think this is really good- I like all of the terms you used and hoe detailed you were. Great Job! :)
ReplyDeleteI know I'm commenting again . . . but don't forget that if the combustion chamber is too small, then oxygen will become the limiting reagent and the reaction will not complete.
ReplyDeleteI think you did a great job with the description of the construction process. Like Sammi said it is very detailed. I wouldn't change anything other than adding some pictures to match the text. Great Job though!
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