Recent content by MagnetDave

Given that you have asked such a broad question, one can hardly "prove" anything. However, let's just think through the question, shall we? We are getting some kind of resonant effect at frequency f. Let's suppose it's a dielectric effect (given what you're described, that seems most...

yes yes yes...however, to be responsive to the OP in as direct a manner as possible as to why the cue doesn't fly back as far as the target ball, it is reasonably fair to ignore friction, spin, and elasticity. I was simply trying to say, to OP, WHY a cue ball squarely striking an object of...

Absolutely nothing. You'd be at the wrong frequency.

Let me put this a bit more simply: The cue ball imparts a force on the target ball equal to the force you hit it with (ignoring friction, of course). Let's call it X Newtons. X Newtons accelerates the target ball from 0 to the speed of the cue ball. In turn, the target ball imparts an equal...

You have a conceptual issue here: There is no such thing as "cold." This is merely an issue of how your body perceives temperature. Think of it this way: If I connect a warm room to a less-warm room what happens? Obviously the heat flows from the warmer room to the less-warm room (though a...

That much water will be hard to freeze that fast, and it has more to do with the water. Water has a limited thermal conductivity and a large specific heat and specific heat of fusion and you have to absorb quite a bit of energy to get that water frozen, and then you have conduct the energy out...

Why would you want to? Realize that "ferrofluid" is a suspension of magnetic particles in oil, and that we have a simple version for lubrication called "oil" that you can get in pretty much any viscosity that you want.

Your question is extremely general to the point of being unanswerable. How much water do you want to freeze how fast? This would be a good start.

The result is heavily dependent on the geometry and material of the situation. A "bar" magnet encompasses a wide variety of things that all perform very differently. If you envision your bar as a thin sheet, with the direction of magnetization in the thin axis, it will be close to useless...

Styrofoam has a dielectric constant that is very close to 1 (being a large volume fraction air). So, it really won't do much. Most plastics have dielectric constants between 2 and 5, so I would recommend something more interesting. ceramics can be more interesting, as could ice. Second item...

It's hard to characterize the variety as "wider." There are certain compounds only stable at cryogenic temperature (and things like Bose-Einstein condensates) but there are also compounds only stable at higher temperatures. What is generally more significant is that the kinetics of the...

Simple question, complicated answer: For practical purpose, in the attracting pole case, nothing interesting happens. The field lines merge and the two smaller magnets effectively behave as a larger magnet. For practical, permanent magnets, usually nothing happens to the magnets themselves...

I would bet that thermal expansion (or contraction in this case) of the various materials in your instrument has a much more pronounced effect than the density of air. Secondarily, you may, in some cases, have material stiffen and/or embrittle as well, and that would also have an effect. If...

There is nothing conceptually wrong with what you describe. Heating up a hydrated crystal will drive the water off and make it anhydrous. I'm not sure how you make any of that useful, but your understanding of the chemistry is sound.

The reason that this is not the safe assumption is because of the placebo effect. It is extremely well-documented that humans will respond positively to no treatment at all if they think they are receiving one. Therefore, in the case of things are purported to have medical effect...