Recent content by clmech

I was only quoting a previous reply to my question when I used the ‘typical’ word. If I still had the text of that task I’d post it, but unfortunately all of this is being derived from my memory right now. Though there was spinning involved for sure, that’s why I guessed friction was necessary...

Yes, understood, unfortunately I don’t have the text of the task anymore, but this helps. Thank you.

So, to clarify, in a typical yo-yo problem we usually disregard static friction?

I accidentally replied to both answers here, sorry about that.

Yes I suppose I meant kinetic friction (Sorry, I just translated it directly from my language, I should’ve double checked the english terms). I’m not sure if dynamic is another name for kinetic friction, but that’s what I was thinking about. Thank you for the clarification on the first part.

Static friction? Also, if so, then I’m very confused, as we disregarded it in a task about a yo-yo; or, to be precise I wrote some equations including static friction and the teacher wrote back that it was not necessary to include it. It was just a regular yo-yo without dynamic friction and the...

Thank you, that makes sense, can I ask about systems with strings though? For example a pulley or something rotating attached on a string; Is friction necessary then, for the pulley or the object to even be rotating?

As far as I’ve gathered, for a system to rotate there has to be some static friction acting upon it and dynamic friction can be zero. But now I’m a bit confused about this as we completely disregarded static friction in some tasks where a system was rotating. So was my original assumption wrong...