Help me understand a misconception....

[asterroc]

An interesting situation came up in my Physics class today, where two of my students surprised me with a question they asked. To try and understand their thinking so I can teach the content better, I'd like to ask that everyone take a look at the below situation and tell me what you think will happen. I don't care if you know any physics or if you're a professional ear-wax taster, I want to know what you think and why.

In the picture below, Box 1 (m₁) is hanging from a string that passes over a pulley. There's no friction in the pulley, and the pulley has no mass, so it can spin freely. The string is then connected to Box 2 (m₂) sitting on a table. For simplicity, let's assume there's no friction on the table - there's some lubrication between the box and the table.



[Poll #1162218]

X-posted a couple places.

Comments

[rosefox]

Right, I get that, but I don't think it's obvious because the puzzle is a mix of things that are stated very clearly ("there is no friction between the table and the second box") and things that are put in very vague terms ("heavy" and "light"), and it's really hard to tell what unstated things to assume unless you've seen lots of puzzles like this before. I might as well assume that box 2 and the table are both magnetized and strongly attracted to each other, or that gravitational attraction goes up rather than down, or... whatever I want, really.

[zandperl.livejournal.com]

The specific situation I gave my students had numbers. I didn't want to confuse readers by making them think that they needed to do math here. If it would help, I think I had around 4.5kg for hanging Box 1, and 8.3kg for Box 2 on the table.

Magnetism is a different course so would not be discussed here.

[rosefox]

Unless you give us the phrasing you gave your students, I can't see how our feedback can possibly be useful to you.

[zandperl.livejournal.com]

What I gave to my students was the picture with numbers on it, and words said aloud that I cannot recall verbatim but were similar to what I said. Since this is a text medium, I am not capable of giving the exact format I gave to my students.

What I am expecting from my readers here is that they internalized the situation from the text and picture, much like my students internalized the situation from the audio and picture, and then applied their own preconceived notions in the process of analyzing it, and spit out an answer. I'm trying to understand the process by which people internalize the situation, and the preconceived notions in their heads. You've already shown me that the exact format (wording, sequence, etc.) in which I present the material can make a difference for some people, which I wasn't consciously aware of.