# Ib Extended Essay in Physics

#### bignik

Hello!
I'm currently in my junior year at an IB school. It is time to choose the subject and the topics for our extended essays, and I am thoroughly convinced of writing an experimental paper in Physics. The point is that I need help on the topics. One fundamental problem is that they ask us to take such important decision before the end of the first semester in our first IB year, which, from a certain point of view is good because we work in advance, but on the other hand we do not have a sufficient knowledge of the subject to judge which areas interest us the most.
As a matter of fact, I have little background information on which to base my decision as all we have covered in the course up until now is physical measurements + error propagation and machanics.

Nonetheless, I have one idea which I think is feasible (but then again I cannot be certain as I do not have sufficient background knowledge) and it would be to build a multi-stage (probably dual) electromagnetic projectile accelerator or coilgun.
It would consist in placing a ferromagnetic sphere in a barrel which is surrounded by two solenoids (powered by capacitors). As the projectile is accelerated by the magnetic field, as it approaches a given (calculated I presume) point between the coils, the first solenoid would have to be shut off. I was thinking of doing this through a microcontroller such as the Arduino (which can be easily set up through some C coding) which would be triggered by the closing of a simple circuit given by the bullet crossing the given point in the barrel.
My experiment could consist in comparing some "output" values such as velocity/acceleration/Kinetic Energy of the projectile to changing "input" values such as voltage, current, capacitance. Or I could calculate efficiency and similar calculations.

...i honestly donno because, as I said, my knowledge on the subject is very limited. Nonetheless, I am certain that the necessary information is part of the syllabus, its just that we haven't covered it yet.

What do you think of this idea?
Any other ideas would be very much appreciated.

#### General_Sax

Nonetheless, I have one idea which I think is feasible (but then again I cannot be certain as I do not have sufficient background knowledge) ...
Then how is it a feasible experiment/essay for you to do?

Nonetheless, I am certain that the necessary information is part of the syllabus, its just that we haven't covered it yet.
You're sure that the necessary information to build a coilgun/railgun/whatever is in the syllabus?

I suggest you tone down your project/essay and do a well written one using topics that are covered, ie, make it more simple and do it very well.

#### AlephZero

Homework Helper
What General-Sax said. I think your first task is to focus on the SPECIFICS of what topics your essay is going to cover. The general idea of "a railgun or coilgun" might sound cool, but there are thousands of websites about those topics (ranging from serious engineering and science, down to complete garbage) so whatever you write it may LOOK to the examiners as if you plagiarized most of it, even if you didn't!

I would suggest you select a "smaller" topic where you can design an experiment to investigate or demonstrate some phenomenon, and (most important since this is a science project) MEASURE something. That experiment could be something to do with electromagnetism that could be used as part of the process of designing a coil/railgun if you want, but just "building a gun and getting it to work as well as you can" is too unfocused, and probably a far too big a project for the time you have.

If you haven't done much "original" experimental work before, you will find that everything takes MUCH longer that you thought it would (usually because nothing works properly the first time, and sometimes it still doesn't work the tenth of hundredth time.) Find out how much time you should be allocating to this part of your TOTAL course work. I don't know any details about the IB, but I would be surprised if you were meant to be spending hundreds of hours on this one essay.

You might also want to think about "boring" stuff like health and safety. What you do with a coil gun in your own back yard is your own affair, but what you can do in a school or college lab might be more restricted, for the obvious reasons.

#### bignik

General Sax, the main point of an experimental Extended Essay is that it is supposed to investigate something that is not within the Syllabus but that has its fundaments lying within it.
This case, I believe, does satisfy these requirements, as the information necessary for circuit calculations is within the syllabus. Similarly, coils and electromagnetism are covered. Yet, applications of such concepts with the integration of electronics (the microcontroller) would be carrying it beyond what is discussed in class.
This said, I would also like to thankyou, AlephZero, too for your observation. You say that the important thing is measuring something. The point is that I do. As I said, I would be investigating the relationship between some input value such as voltage or capacitance and the resulting effect on the accelerated bullet.

By the way, I am basing such an approach to my essay on the fact that a senior from last year at my school wrote an extended essay building a Parabolic Trogh Collector and discussing its (measured) efficiency. In his conclusion, he compared it with the (measured) efficiency of a commercial solar oven. He ultimately earned top marks.
In reference to what you said (AlephZero) regarding plagiarism, PTCs are, if possible, an even more discussed subject on the internet, with it being related to renewable energy etc., and he did not have any such problem. With the IB, as long as you cite sources and you verify their reliablity, you are fine.

I do realize that the project I'm proposing would be highly time consuming (as was his anyway) and would go beyond the theoretical 40 hours that the IB suggests for the Extended Essay, and that I realize is a problem.

At any rate, given these new considerations and batch of information, do your points of view (and consequently suggestions) alter in any way? :)

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