Competition “Physics Cup – IPhO2012”

Eligibility: age- and educational restrictions for the participants are the same as for IPhO-2012.

Registration: please send e-mail to, indicating:

  1. Your given name;
  2. Family name;
  3. Date of birth;
  4. E-mail address;
  5. Full mailing address;
  6. Your school;
  7. Your physics teacher

It is recommended to register as soon as possible, prior to the publication of the first problem (18. Sept. 2011). However, you can also register at any later stage.

Distribution of problems: At 2 pm (GMT) of the third Sunday of each month, between September 2011 and June 2012, a new problem is published at the homepage of 43rd IPhO ( and also sent by e-mail to all the registered participants.

Submitting the solutions: The contestants are asked to submit the answer as fast as they can, but not later than the publication time of the next problem. The formulae can be submitted using the LaTeX symbols; these can be included directly into the e-mail text (e.g. m=m_0/\sqrt{1-v^2/c^2}). Alternatively, these can be also submitted as formulae in OpenOffice or MSWord files, or scanned (digitally photographed) images of a clear handwritten text. Also, the students are asked to send their solutions (using one of the above mentioned formats), but this can be done with a delay of up to 48 hours (from the moment of submitting the answer). These solutions should contain as few text (in English) as possible (few words are typically enough), mostly using formulae and figures. When sending solutions, please use the subject line "Problem No 1" ("Problem No 2", etc), exactly as written here (but without quotation marks); in that case you will receive an auto-reply confirming that your solution has been received. If you do not want to receive an auto-reply, make sure the subject line does not contain (not necessarily begin with) the text "Problem No 1" (for instance just drop "No" and write "Problem 1").

Grading: Each problem costs 1.0 pts; this serves as a base score, which will be multiplied with factors corresponding to bonuses and penalties. Either a full or zero credit is given; on a weekly basis (for the first three weeks on Sunday, for the fourth week on Thursday), the competitors are notified if their solutions are (a) complete, (b) incomplete (e.g. some missing motivations), (c) with minor mistakes, or (d) incorrect. Cases (b)-(c) incur a penalty factor of 0.9 and the case (d) – 0.8. The students can send the corrected solutions – either upon finding an error or receiving the notification of incompleteness; each revision incurs a penalty factor of 0.9. The first 10 correct answers (supplemented later with a complete solution) receive a bonus factor according to the formula k = 1.111-n, where n is the order number. The best solution will receive a bonus factor of e (=2.718…) and will be published as the official solution at the web page. If there is no single solution, which is better than the others, the factor e may be distributed over several solutions of similar quality — in such a way that the product of all the factors equals still to e. If, in addition to the best solutions, there are other good solutions which (due to certain reasons, eg. the usage of a significantly different approach) deserve publishing, these published alternative solutions will receive a bonus factor of 1.1.  There is also an additional rule for those who send many incorrect solutions before finding a correct one: if the product of penalty factors with the speed bonus factors gives a number which is smaller than e-2/3, the factor e-2/3 is used, instead. Example: a student submits an answer, discovers an error and therefore submits a revised answer (k1 = 0.9), together with the solution; upon being notified that the solution has still a minor mistake (k2 = 0.9), he submits a third revision (k3 = 0.9) of the answer and the solution. This solution turns out to be the fifth correct solution, so k4 = 1.16; later on, it is found that this is the best solution which will be published at the web-page (k5 = e). Thus, the overall score will be 0.93×1.16×e = 4.673…

Publication of results: The names and results of half of the students with best scores are published at the web-page; the list is updated monthly.

Distribution of awards: The awards are announced and handed over at the closing ceremony of the 43rd IPhO or sent to the mailing address (if the recipient is not present at the ceremony).

In your solutions what you may assume well-known and what not: things which are not in the formula sheet need to be motivated/derived. (You don't need to check – your typical high-school formulae are there.)

Questions regarding the competition: e-mail to

See also: Frequently asked questions.

Problem No 0 – you will not receive points for this, but you can submit your answer and let us know how long time did it take for you to solve it.