How should I ask general physics questions about numericals?

Question

Just wanted to ensure something. I am new to this website. I am in high school and preparing for physics olympiads. So suppose I face some problem or have a question while solving numericals for books like Irodov Or HC Verma can I ask my question here? Will that be considered homework problem? Of course I have read through the homework policies and everything and surely I'll provide my approach and show my efforts whenever I post a question. But are such numerical based questions entertained here or are they considered homework? How should I frame my questions?

Answer 1

By "questions about numericals", I imagine you mean questions like this one from Irodov:

This is quite a general pattern in homework set questions: a (fairly artificial) setup is proposed, with numerical values for properties p₁, ... , p_n, and you're asked to give a numerical value for property p_n+1.

For such sorts of questions, and regardless of whether your motivation for solving them is self-study or formal homework set by an instructor:

• If you post a question that only has the problem and asks "what do I do?", it will get shot down pretty much immediately.
• If you post a question that quotes the problem, provides your working for the problem, notes that your final value is not what it's supposed to be, and asks for help, then you are asking a check-my-work question, which are usually considered off topic.

More generally, if your post crucially depends on the specific numerical values set by some textbook author, then it is unlikely to find a good reception here. We want conceptual questions which are useful to people that are not staring at the same specific set problem in the same specific edition of the same specific textbook that you are.

Let me provide an example to try and clarify what we mean by that. For the problem quoted above, there are two main steps you need to do: you need the charge density of the cylinder, and you need to transform that into the current. There are thus two main conceptual questions which would be on topic for this site:

• How can I get the charge density of a cylinder from the electric field on its surface?
• What is the "convection current" for a moving charge distribution of density ρ?

Note that both of these questions demonstrate that you've thought about the problem and you have identified the concepts that are important for solving it - we can then help you grapple with those.