Stuck on a physics problem? Post it here. Help others work through theirs. Tag by subfield. Mark solved when answered. Show your working.
This category exists for one purpose: to help you get unstuck. Whether the problem comes from a problem set, a past-year exam, a textbook, a competition, or your own curiosity — if you have tried and hit a wall, post it here. There are students, alumni, and faculty in this community who have almost certainly seen something like it before.
Before Posting
Attempt the problem seriously. This category is not a solution-request service. A post with no working will be closed. Beyond the rules, it is also practically useless — if you do not show where you got stuck, no one can help you at the right place. Work through what you can, identify precisely where your reasoning breaks down, and bring that to the forum.
Search before posting. There is a good chance your problem or a closely related one has already been discussed. Use the search bar with relevant keywords and check the relevant subfield tag before opening a new thread.
Writing a Post
1. The complete problem statement. Write out the full problem, including all given quantities, conditions, and what is being asked. Do not link to an image and leave it at that — type it out. Use LaTeX for all mathematical expressions. Inline expressions go between single dollar signs $...$ and display equations go between double dollar signs $...$. A post full of images of handwritten equations is harder to read, harder to search, and harder to answer.
2. Your attempt. Show all the working you have done so far, step by step. If you tried two approaches, show both. Do not summarise your attempt in prose — write the actual mathematics. This is the most important part of your post. People helping you need to see your reasoning, not just your conclusion.
3. Where you got stuck, precisely. Do not just say “I don’t understand this.” Say: “I obtained this expression at this step, and I expected it to simplify to this, but instead I get this, and I do not understand why.” Or: “I am not sure which principle applies here — I considered X and Y, but X fails because of this reason and I do not know how to evaluate Y.” Precision here is everything. The more precisely you identify your confusion, the faster and better the answer you will get.
4. What you think might be going wrong. Even a wrong hypothesis is useful. It tells the reader what you have already considered and rules out certain responses. Write it down even if you are not confident.
After Posting
reply that resolved it. This is not optional — it is how this category remains useful as a long-term archive. Future students searching for similar problems need to know at a glance whether a thread has a verified answer. A thread full of discussion with no marked solution looks unresolved even when it is not.
If multiple replies together constitute the answer, note this in a final reply of your own before marking the most essential one as solved.