Recent content by abccbaabc014

Ah, I get it. They're not field lines, but because each iron filing is magnetized in the field, they all line up end to end. Thanks for the replies.

I'm not sure I made myself well understood. I mean: What are field lines? I've been sort of thinking of them like contours in the field (as in, they depict lines of equal field strength), but that doesn't explain why the filings line up on them. I've got a feeling this may have to be a...

Hi. I was thinking about magnetism, and remembered the classic experiment to show magnets working. Basically, you put a magnet under a piece of paper, and drop iron filings on the paper. The filings all line up along lines that curve between the poles. My question is, what are those lines? The...

The wikipedia article on Kinetic Energy: http://en.wikipedia.org/wiki/Kinetic_energy "Kinetic energy for single objects is completely frame-dependent (relative). For example, a bullet racing by a non-moving observer has kinetic energy in the reference frame of this observer, but the same...

Alright, thanks a lot.

With my fairly sketchy knowledge of relativity, one of the basic assumptions is that you can't tell who's point of view is right, with regards to how thing are moving. But, in the case of rotation, isn't it possible to tell if you are rotating by observing the coriolis effect? For instance...

Right, I'll try to get this question across. Say you have 2 bar electromagnets, aligned so when you turn them on they are attracted to each other. You start with them touching, turn them on and pull them apart. You then turn of the current and put them back together. If you continue to repeat...