Here we have a question which is considered to be off topic by some members of the community, but on topic by others (as evidenced by the fact that they answered it). I'm not entirely sure which camp I'm in. At first, I thought it was off topic, but I've been closing a lot of questions recently and since at the time, nobody else objected to the question, I thought I would give it a chance. (Besides, there is physics involved in paper tearing at some level.) However, now it's clear that there are people who consider this sort of question unambiguously off topic, and in many cases I'm inclined to agree with them. So we should make a decision.
Questions about practical phenomena that don't address the underlying reasons: on topic or off topic?
Related meta questions:
- Are "How to..." questions for demos and try-this-at-home experiments on topic?
- What tag should we use to indicate "how does X work?" ?
Other examples of these practical questions (all the ones I could find happen to be closed, but I think there are others out there that weren't; please comment or edit in links if you find them):