find_in_page Overview
SPhL 2022 will be held online on Saturday, 11 June 2022, for a duration of 4 hours, from 9:00 AM to 1:00 PM (Singapore Time, GMT+8).

All participants must be current students in Singapore secondary schools or junior colleges (or equivalent).

You must form teams of 3, 4 or 5 members, under one of these two categories:
  • SPhL (Junior): All members are studying in secondary school (or equivalent)
  • SPhL (Senior): All members are studying in junior college (or equivalent)
Students in a team can come from different schools.

Teams will be ranked based on the points scored by correctly solving problems. Rankings and awards will be determined separately for each category.

Your team will share one account on our competition platform, which may be accessed on all of your teammates’ devices simultaneously. Every action you make there will be performed collectively for the whole team. Be sure to share the account details with your teammates, and everyone must keep it secure!
rule Do’s and Don’ts
During the competition, you’re allowed – in fact, strongly encouraged – to communicate with your teammates in any manner you deem fit, be it virtually or in person. You may compete from any location of your choice.

You’re also allowed complete, unrestricted reference to any resources that you are legally permitted to access. This includes non-exhaustively: your own notes, textbooks, online resources (e.g. courses, videos, simulations, animations) including those found using a search engine like Google, computational software (e.g. Desmos, Wolfram Alpha), or computer programming languages (e.g. Python, Julia, C++, Mathematica, MATLAB).

However, you cannot communicate with anyone outside of your team regarding the SPhL problems during the competition. Any discussion of problems must be confined within your team. But once the competition ends, this restriction no longer applies!

You’re also strictly prohibited from any unsporting or unethical actions that unfairly advantages or disadvantages yourselves or other teams.
quiz Problems
Problems will vary in difficulty level, but are generally arranged in order of increasing difficulty (though this is, of course, somewhat subjective). The examinable syllabus will follow that of the International Physics Olympiad (IPhO). For a sense of possible question styles, please refer to the SPhL 2021 problems, or the sample problems for SPhL 2021.

Teams in both categories will mostly attempt the same problems – with the exception of a number of “Junior Problems” that are only released to the SPhL (Junior) teams.

Answers to all problems will be numerical, and should be given in the units specified in the problem. The degree of precision of your answers should follow, at minimum, the number of significant figures stated in the problem.

If the problem statement specifies the numerical value of a constant, use that value in your calculations. Otherwise, use their standard values, e.g. g = 9.81 m s-2. You may refer to this data sheet for the standard values of common constants.
lock_openUnlocking Problems
At any time during the competition, your team can concurrently access up to 4 problems to work on.

Whenever you have fewer than 4 problems to work on, you can unlock (i.e. gain access to) a new one. This happens whenever you solve or skip a problem, or at the very start of the competition (when you have yet to unlock any problems).

You will be given a limited choice on which new problem(s) to unlock. You will be shown only the titles and allocated points of the next 4 problems that you have not yet unlocked – all other details, such as the problem statement, will not be revealed. Based on this little preview, you are to then decide which one of those 4 problems to unlock.

For illustration: Example scenario of unlocking problems
To help you better understand the problem unlocking system, let’s consider a mock competition with problems numbered 1 to 10. A possible sequence of actions could then look like this:
At the start of the competition, you do not have access to any problem. You will be able to unlock a new problem up to 4 times in succession.
Problems not yet unlocked: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
You can pick one of problems 1, 2, 3, 4 to unlock. You select problem 1.
Problems not yet unlocked: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Now, you have access to problem 1, which you can start working on. At the same time, you can still unlock a new problem 3 times.
You can pick one of problems 2, 3, 4, 5 to unlock. You select problem 3.
Problems not yet unlocked: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Now, you have access to problems 1, 3. You can still unlock a new problem 2 times.
You can pick one of problems 2, 4, 5, 6 to unlock. You select problem 6.
Problems not yet unlocked: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Now, you have access to problems 1, 3, 6. You can still unlock 1 new problem.
You can pick one of problems 2, 4, 5, 7 to unlock. You select problem 4.
Problems not yet unlocked: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Now, you have access to problems 1, 3, 4, 6. With access to 4 problems, you are no longer eligible to unlock a new problem… until you solve or skip one of your unlocked problems.
Let’s say, you submit a correct answer to problem 3.

You already had access to problems 1, 4, 6. You can now unlock 1 new problem.
You can pick one of problems 2, 5, 7, 8 to unlock. You select problem 7.
Problems not yet unlocked: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Now, you have access to problems 1, 4, 6, 7. With access to 4 problems, you cannot unlock a new problem, until your next solve or skip.
You will then be allowed to unlock one of problems 2, 5, 8, 9.

… and so on!
uploadSubmitting Answers
Once you submit an answer to a problem, the platform instantaneously processes it and informs you whether it is correct or wrong.

done If your answer is correct:
  • You will be able to unlock a new problem.
  • You will also be awarded points (elaborated later).
close If your answer is wrong:
  • You will not be able to unlock a new problem.
  • Instead, you may re-attempt the problem, as many times as you wish. But the points awarded when you do eventually solve it decreases with the number of attempts taken (elaborated later).
  • To discourage random guessing, you have to wait at least 30 seconds before re-submitting an answer to the same problem.
Each problem is allocated a number of points, which will be fully awarded if the problem is solved on the first attempt. If a problem is solved after multiple attempts, the formula is “points awarded = (points allocated to that problem) – (number of incorrect submissions made for that problem)”. If this calculation yields 0 or negative points, the points awarded will be instead set to 1 point. In other words, the general formula is:

Points awarded = max(1, p),

where p = (points allocated to that problem) – (number of incorrect submissions made for that problem).

For illustration: Table of points awarded
To help you better understand how many points are awarded under different scenarios, here’s a table to clear things up:

Points awarded for a correct answer

skip_nextSkipping Problems
You may also skip a problem in order to unlock a new one. This may be useful if you’ve been stuck on a problem for a long time.

Once a problem is skipped, 1 point is deducted from your total score, and the skipped problem can no longer be attempted.

The system will also automatically grant a “free skip” if your team has not gained any points for 30 minutes (i.e. no correct answers submitted to any problem in the last 30 minutes). To use the “free skip” option, you would need to choose one problem to permanently skip, which will be removed from your unlocked problems without any point penalty.

Multi-part problems
A multi-part problem comprises a number of distinct smaller parts labelled (a), (b), … etc. Each part asks a different question, carries a different number of points, and (usually) has a different answer.

When you unlock a multi-part problem, you simultaneously unlock all of its constituent parts. The preview of unlockable problems (that displays while unlocking a new problem) will not indicate whether a problem is multi-part, and the point allocation displayed there for a multi-part problem would be the total points of all parts combined.

You submit answers to each part independently, and in any sequence you want. Likewise, points are awarded separately for each part. A new problem is only unlocked once all parts of the multi-part problem have been solved.

If you choose to skip a multi-part problem, you will skip all of its remaining unsolved parts. Unless a “free skip” is used, the 1-point penalty applies, but it is only imposed once for the whole problem, regardless of the number of unsolved parts skipped. Hence, you may, for instance, gain points for some of the parts and then skip the remaining parts for a combined penalty of 1 point.

Multiple-choice problems
Instead of an open-ended numerical answer, multiple-choice problems simply require you to choose from a few specified options labelled Option 1, Option 2 … etc.

Unlocking, submitting, and skipping rules for multiple-choice problems are no different from any other problem.

The only difference is with the awarding of points. With enough incorrect attempts, you may score a minimum of 0 points for the correct answer to multiple-choice problems, as opposed to the minimum of 1 point for all other problems.
hourglass_top Half Hour Rush
help_outlineWhat is HHR?
Half Hour Rush (HHR) is a 30 min period that commences at 10:30 AM, i.e. 1.5 hours after the start of the competition, and ends at 11:00 AM.

During HHR, we introduce 3 sets of fresh “HHR problems” into the competition: Mechanics (M), Electromagnetism (E), and Others (X). Each set contains 4 HHR problems arranged in increasing order of difficulty. Each of the 3 × 4 = 12 HHR problems is labelled based on which set it belongs to (M/E/X) and its index within the set. For instance, the first problem in the Mechanics set is “M1”, the fourth problem in the Electromagnetism set is “E4”, etc.

Once HHR begins, all teams will automatically gain concurrent access to the first problem from each set: M1, E1 and X1.

Submitting, skipping rules, and points awarded for HHR problems are no different from any other problem. However, the system of unlocking HHR problems differs significantly – there is no element of choice, and the problems are unlocked automatically when triggered as explained next.

When you solve or skip a HHR problem, you automatically gain access to the next one in that same set. For instance, upon solving M1, you immediately gain access to M2.

Accessible HHR problems are not counted as part of the 4 problems that you can access concurrently. Hence, if you have outstanding unsolved HHR problems, you can essentially access up to 7 problems at any time: 4 regular non-HHR problems, and 3 HHR problems. However, it is beneficial for you to focus on HHR problems during the Half Hour Rush, as we’ll now explain.
auto_awesomeWhy bother with HHR?
Here’s the significant benefit of HHR: You can receive double the points scored if you solve HHR problems in “triplets” during the Half Hour Rush period. For instance, if you correctly answer M1, E1, and X1 (in any order, without skipping) but before solving any of the second problems from each set (i.e. M2, E2, or X2), the total points gained from answering M1, E1 and X1 will be doubled. The same applies to subsequent problems in the sets.

For illustration: Example scenarios of triplets and non-triplets
Suppose that during the Half Hour Rush, your team solves HHR problems in the following chronological sequence (from left to right) with the following scores:

Problem E1 M1 X1 M2 X2 E2 M3 E3 M4
Score 3 3 2 4 3 1 4 2 4


Points directly scored from solving HHR problems = 3 + 3 + 2 + 4 + 3 + 1 + 4 + 2 + 4 = 26.

Additionally, two triplets were formed: {E1, M1, X1} and {M2, X2, E2}. Bonus points awarded for reaping triplets = (3 + 3 + 2) + (4 + 3 + 1) = 16.

Hence, your team would score a total of 26 + 16 = 42 points during HHR.

On the other hand, consider another team that solves in this sequence (noting that the points scored for each question can differ due to the effect of re-attempts):

Problem X1 E1 X2 M1 E2 E3 M2 X3 M3
Score 3 3 3 3 4 4 4 5 5


Points directly scored from solving HHR problems = 3 + 3 + 3 + 3 + 4 + 4 + 4 + 5 + 5 = 34.

However, no triplets were formed, so no bonus points would be awarded. Hence, despite this team scoring more raw points from solving the problems than your team (34 instead of 26), your team gained more points in total because of the bonus from triplets.

This other team could have coordinated better by simply swapping the order in which they submitted answers for X2 and M1, as well as for E3 and M2. This would have given them 3 triplets with 34 bonus points, doubling the total points they scored from HHR to 34 + 34 = 68 points.

You can still access and solve the other 4 regular non-HHR problems during the HHR period – but we advise that you focus exclusively on the HHR problems during this time, and work to reap triplets and score bonus points!

Once the HHR period ends, you can still submit answers for HHR problems to gain points and automatically unlock additional HHR problems. However, you will no longer reap bonus points from completing triplets.
textsms Final Remarks
By registering for SPhL, you agree to comply with all of the aforementioned rules.

Leaderboards will only reflect team names, and not the individual names or emails. Personal data will not be publicly displayed on the website without prior consent.

Should you be judged to have breached any of the rules, we reserve the right to impose penalties, including but not limited to disqualification of your entire team.

After the competition, you may submit appeals on the grounds of any issues with the problems or solutions, or objections to penalties imposed by the organisers. If an appeal is accepted, we will update all scores and rankings accordingly.

All scores will be final and no further appeals will be entertained 24 hours after the end of the competition.