# International Physics Olympiad (IPhO): Assistance is needed!

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1. Aug 8, 2013

### Daniel Luo

Hey

I'm a Danish student, who will start 11th grade after summer.

I intend to get to the International Physics Olympiad 2014. I'm familiar with almost the whole syllabus, but I'm not strong in calculus yet (I know basics of differential equations and integration). Furthermore, I try to do "Irodov's Problems in General Physics" to enhance my problem solving skills. On top of that I study "An Introduction to Physics" by Cutnell, and intend to start studying University Physics by Young and Freedman. My dream is to become a recognized theoretical physicist. The problem with University Physics is I'm doing it for self-study. Should I do ALL the problems, or just the odd-numbered (there are answers only to odd-numbered problems)?

Any other advice in my preparation to IPhO? E.g. recommendation to problem-solving books that fits my level?

Thanks.

2. Aug 8, 2013

### verty

My advice is to learn calculus right away, MIT's OCW stuff is great for this, and get studying University Physics as soon as possible. I think this order would be good: single variable calculus, mechanics, multivariable calculus / some diff equations (not a lot), E&M. I find multivariable calculus to be quite difficult, it is more abstract and the problems are more contrived. I think treat that as phase 2 and master the single variable stuff first.

As for which problems to do, do every problem unless the problem you are about to do is just like one you have done before. You'll soon start to recognize the type of problem, you'll see in your mind the steps you would follow to solve it, then you can skip it. This is the litmus test for knowing the problems well enough.

That said, it is very important to know the math very well. It's a combination really of knowing the physics so you can translate the problem into a math one, and knowing the math so you can solve the problem in the most efficient way. So I would err on the side of learning the math first. Calculus in particular gets easier when you know the whole subject. Learning it first may be worthwhile.

I don't have recommendation for problem books but I can think of something that might help. There is a test in the USA for lawyers, the LSAT. It has a logic component and those logic problems are very good indeed. It isn't related to physics but it'll get your logic/analytical brain working efficiently. So a prep book for the LSAT might be valuable.

Otherwise, learn the math as well as you can. Mastering the math will be the difference between flying through the Olympiad problems or hitting road bumps.

-- Hmm, now that I think about it, this LSAT idea would be specific to the US, it wouldn't work. Ok, forget that.

Last edited: Aug 8, 2013
3. Aug 8, 2013

### verty

What I was talking about when mentioning the LSAT was questions like this one:

It looks scary but this analytical thinking can help when it comes to deciphering problems. But this is very optional, of course. Strictly for fun, I'd say.

Best of luck to you.

4. Aug 9, 2013

### Daniel Luo

How much calculus do you think I would need? Besides, I've heard a lot about whether Halliday Resnick or University Physics is best; what is your opinion?

5. Aug 9, 2013

### GregoryGr

Well hello, I was in IPhO this year at your country :P.
Can't really give you any tips, as the only preparation I did was looking at the old topics, since I had my countrie's exams to enter a university to do, and we don't get much support over here. (from other students I've learned that they have some sort of physics camp, where they stay there and learn a lot, usually from these countries they were getting medals as well, so it works well).

Irodov's general problems is a VERY good book, probably the best you can have (sucks for me, the first time I studied it was AFTER the olympiad :D ), and for maths, I can't help you, the maths needed for the olympiad are the ones I had to study to get into uni, but you can find those on the net.

Best of luck with the olympiad. And don't worry, if you're going prepared you're going to do well.

6. Aug 9, 2013

### verty

I would say, all of single variable calculus, all of multivariable calculus (for E&M, divergence/curl, etc are motivated by concepts from E&M; there is benefit to be had if you can get a solid understanding of them), then I guess first order ODE stuff. This may not be necessary though, and it would come right at the end anyhow.

Regarding your second question, for me, University Physics is great, it covers everything you need, you really don't need another book. I think you could go on to the IPhO past problems with not too much trouble after getting through it. That said, it is not known to be difficult. I imagine there are books out there with more challenging problems, but for me it is better to get a complete understanding before ramping up the difficulty.

7. Aug 10, 2013

### Daniel Luo

Thanks for the replies verty and GregoryGr.

#GregoryGr

What books did you use? How did it go at the Olympiad? And what country did you represent? :D

Anyways, I started studying calculus and 'University Physics' (while solving as many problems as I can in Irodov's).

8. Aug 10, 2013

### GregoryGr

I didn't use any books, one week before the olympiad we had some professors teaching us physics, but that was pretty much it. Before that I just read some of the older theoretical problems (I knew that I was hopeless at the experimental, because we never do such things in Greece, at least in public schools).

I underperformed in the theoretical exams, I don't know if it was just my brain malfunctioning from the little amount of sleep I was getting, or the fact that we had around 10 people watching us, and every few moments on of them would take a picture, also a cameraman from a danish tv would pass by. Generally, the conditions didn't make it easy for me to focus, and even though I believed I would get a honourable mention, in the end I got nothing.
Didn't put much effort in the experiments, to understand the scale of my cluelessness, it was the first time I touched a multimeter and I had no clue what a variable resistance looked like or how to actually change the resistance. At least I went good on the other problem with the optics, but failed utterly at the electrical one.

As my name says, I represented GR (Greece) :D .

I have a question for you, how do you know that you will be at IPhO this early? I found out in May 2013, and I had exams for school until late June, so you see why my preparation was non-existant! If you can handle differential equations and solve irodov, while being calm @ the olympiad, I believe you are sure to get a prize.

PS1: I had to clue how to use the multimeters either, thank god they had the settings they wanted from the box, otherwise I might've got 0/12

PS2: Don't get too caught up in the competition in IPhO. There were many people this year solving physics with every chance they got, which I believe is pointless. You're going to a foreign country, which you've probably never seen before (it was the first time for me in Denmark), so try to enjoy the trip and meet some people. I have good memories from hanging out with the guys from my team+ some other countries'. Didn't really speak with the danish team though :\

Last edited: Aug 10, 2013
9. Aug 10, 2013

### Daniel Luo

I haven't qualified yet. I have to get past first round, then second round, then national finals and finally the olympic team. I am just preparing in good time. I have been preparing almost a year now. First round is end of October/start of November.

By the way, how much experimental preparation do you think I would need? How difficult would you say Irodov is compared to IPhO problems? Would you say that my time is better spent solving tons of problems than learning new concepts (of course after I've gone through the whole syllabus)? My goal is to win a medal at the olympiad =).

I'm truly grateful for your help.

Last edited: Aug 10, 2013
10. Aug 11, 2013

### GregoryGr

Holy *hit, so 2 years preparation? Don't worry, your goal is 99.9% certain to become a reality. I don't really know what to say, like I told you, I didn't have any background at the experiments, most peoples' problem this year was the time, not the difficulty of the experiments, so just be quick ( ) and you should be fine.
The difficulty of problems in Irodov varies much, but I'd say that generally it's on the same level, it's just that the problems of irodov aren't as massive as the IPhO problems, but that doesn't matter much.I don't know how learning new concepts is going to help you much, seeing that they describe new concepts if they put them on the subjects.

Last edited by a moderator: Sep 25, 2014
11. Aug 11, 2013

### lasymphonie

You're preparing two years in advance? That's intense!

I also went to IPhO, though back in 2010, so feel free to message me privately for some candid advice. I had a different preparation timeline to most of the other competitors, which sucked majorly - my country didn't have a summer vacation during IPhO or in the lead up to it, so I had to miss school, but I was taking major exams in June and in October, so I had to cram in IPhO studying around all of my schoolwork (read: I did very little IPhO preparation). The person who I'm currently dating also went to IPhO and though he prepared a lot more than I did, he definitely didn't start studying two years in advance!

I wouldn't say that any textbooks give questions that are good preparation for IPhO as most questions are a lot simpler and are a lot shorter (less synthesis of information). Textbook questions are good for drills: they're good to make sure you know the basic concepts really well and that you know common techniques. Beyond that, they're not useful because they don't teach you how to put together a lot of information in a complex manner and how to pursue a question. The only solution for this is to practice previous IPhO questions, generally in a test environment. I'd recommend to save this for closer to the competition itself, because there are only so many questions!

If you do practice questions, you'll see that some themes come up again and again (rotational motion, etc). Make sure you know how to do the ones that are common.

Also, closer to the date, try some questions from APhO. They tend to be harder than the IPhO questions (or maybe I'm biased because APhO's theory paper was pretty hard in 2010).

12. Aug 11, 2013

### verty

Oh sorry, not long ago I answered two questions like this, one about the IPhO and one about the Putnam Competition. I seem to have blurred them in my memory. The Putnam has extreme requirements, definitely you need the math I mentioned in my last post, but for some reason I thought the IPhO also required calculus knowledge. I see now that it doesn't, the syllabus precludes one needing to know "the extensive use of the calculus (differentiation and integration), complex numbers, or solving differential equations".

Sorry about that. I still think University Physics is a good book and very comprehensive but this means it'll be more advanced than required right now. Although it will give great insight into more advanced problems. But for now, you can hit the problems with impunity I think.

--edit--

This is what I wrote before:

It was geared around what book to buy, University Physics was the quickest/cheapest way to cover all the topics. Knowing calculus would allow learning from University Physics. That was the order of it. I just got mixed up, thinking that calculus was actually required.

Calculus being required, it would have been worthwhile to learn all the math I mentioned, with ODE's at the end just to remove that one last dark corner as well as because you already know some of it.

Last edited: Aug 11, 2013
13. Aug 12, 2013

### lasymphonie

Do be super comfortable with calculus though!!! I seriously think that I'd have done a lot better (I did OK but was disappointed at the time) had I been more comfortable with math.

14. Aug 13, 2013

### Daniel Luo

I have begun studying 'University Physics' and find it to be extremely clear when explaining concepts. The fact that it is a calculus-based textbook truly makes the physics richer.

I have one question to all of you: How can I make sure to qualify to the national team? I'm pretty comfortable with the syllabus for the first round + second round, and partially for the national finals. Do you think it's a disadvantage that I answer the problems in English (I study the IB-programme in Denmark)? How realistic is it to aim for a medal at IPhO?

Thanks a bunch!

15. Aug 13, 2013

### verty

I should say, I only did well in my first math competition before high school, in the other few competitions I entered (all math), I did not reach the final round. The reason for this is I didn't have a complete understanding of any specific thing, I knew enough to answer the usual questions but my methods were not efficient enough for the more difficult problems. I suspect the same may be the case for you, you will need efficient methods to solve the olympiad problems.

I stress that any preparation should be done for enjoyment only, don't push yourself too hard. What you could do is get some past papers and simulate the actual test. Do each against the clock with realistic scoring, perhaps one each weekend, and try to better your score each time. Between these mock tests, focus either on problems you could almost solve, to master them, or on filling gaps that problems seem to fall into. Either way, you will improve your score and any improvement is an optimization.

But again, do it only for fun. Best of luck.

16. Aug 14, 2013

### Daniel Luo

Of course I am doing it because I love it (I want to become a theoretical physicist). Thanks for the advice, but don't you think it's too early to start solving the actual IPhO problems? I've looked at some of them and tried a bit and they seem out of reach...

17. Aug 14, 2013

### verty

My belief is that problems will always look out of reach if you don't know what you need to know to solve them. This is why the advice I give is always to learn the syllabus first. Once you know the syllabus, you have the tools to solve the problems. It may take days to solve them but if you know the syllabus well enough, you should in principle be able to solve any problem on that subject. However, this is not entirely true.

It is not entirely true because the steps needed to solve a problem may be difficult to find. Even knowing the syllabus, you may need to check many avenues to see which one works. And lastly, when eventually you find the secret to doing the problem, you may try to rush because it is now easy and then make mistakes. One mistake and your answer is worthless.

So the crucial skills are knowing the whole syllabus and being able to calculate with no mistakes. Having those skills, then I think you must tackle the problems, although you could start with lesser competitions first.

Have you seen these past papers?

18. Aug 14, 2013

### Daniel Luo

Good point. But on how high a level do I need to learn the syllabus to actually be able to solve the IPhO problems?

19. Aug 14, 2013

### verty

I want to add, I see these competitions as tests of knowledge more than anything. I imagine there are those who would say they are a test of mental aptitude or mental fortitude, and to some degree they are. One needs to mental fortitude to solve the problems without making mistakes and to stay calm throughout, and mental aptitude to solve the problems quick enough, but the difference between you and the person who beats you, on average, will be what they knew that you didn't know. This is fact.

And I wanted to say, this is the biggest hill to climb, 99% of the difficulty, getting to know the subject that well that you aren't surprised by the questions.

PS. I didn't see your last comment. For example, I'm looking at the 1982 IPhO paper, question 1, about a fluourescent tube and impedance. Now impedance is not something one typically learns much about in school. Is it surprising that it appeared in an IPhO paper? Nope. This is my point.

20. Aug 14, 2013

### verty

I think you can answer this question yourself.

Hint: you need to know every concept covered by the syllabus very well. Sorry.

21. Aug 14, 2013

### lasymphonie

Verty, I beg you to take a look at more recent IPhO questions. Take a look at question 3 from APhO in 2010 (http://apho2011.tau.ac.il/.upload/2010 APhO Theoretical Question 3_Question.pdf). Does that seem to be something just based on cramming knowledge?

22. Aug 14, 2013

### GregoryGr

No, honestly, a medal is not an unrealistic expectation, I believe it's nearly impossible for somebody with 1 or more years of preparation to not get a bronze at least! :P
Half the competitors get the medals, and I'd say a good 20-30% gets zero to minimal training before they come, so that leaves you little competition for the medals. Honestly, from the people I met (didn't meet all of them, we were too big a group :P ), all of the guys that had "physics camps" or something of that type in their countries, that prepared them months-years before the olympiad, got medals.
It's not different from any exam really, only in this one, they try very hard to keep you from cheating. I think the fact that they took our cellphones and locked them up in a room is too extreme, it felt like I was going to prison and I couldn't contact anybody from the outside world :P. Just study but not too hard, because if you study hard, you'll want to do good, so much, that it might be destructive. Litterally, I've had this happen (not in IPhO), I wanted to do great but that caused lots of stress and in the end it didn't help. ;)

23. Aug 15, 2013

### verty

Well for me it sort of does. Looking at the first question, there is a question as to how $E_k$ of a gas molecule relates to pressure of the gas. This is something one needs to have learned. I can argue that it makes sense for pressure to be inversely proportional to volume. Halving the volume, there is half the number of places to find the electron, so why should it not double the pressure? This may or may not be right, I don't know, but if I've learned it before, I wouldn't need to guess.

24. Aug 15, 2013

### lasymphonie

We were taught to derive relations...

25. Aug 15, 2013

### verty

Ok. I guess physics is a little different to math. With math, there really isn't time to poke around hoping to work it all out. The problems are too complex for that. The way to beat the odds and the clock is to have seen it before.