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

[catalyst37.livejournal.com]

Well it is an easy question. You would think that on a frictionless surface you would have any force cause box two to move. You should let your students think of it in realistic terms instead of abstract or mathematical if they can not fully grasp them. You should also try and get them to break down the whole question into a couple smaller ones then try to connect them. I am a firm believer that most students who do poorly in any subject is merely laziness in thought. If they can not figure out the question immediately or at least have the logical path of figuring it out they do not try to THINK it through, instead they cut the loss of marks and move on to the next. I know this because I once thought like this, so hopefully this gives you some insight into how your weaker students think. They need to know that this is in most cases the reason for not completing a question and once they know or realize that subconscious process they can correct it.

I hope this helps
Alexzander