# Search results

1. ### What do you call this kind of attraction?

-You get two pieces of dry glass material with perfectly flat faces. -You press and rub them together. Initially, they seem to glide smoothly against each other... -...Eventually, after a few strokes, friction force gets very strong until the point you can't rub them at all. -A this stage...
2. ### Rate of displacement of individual gas molecule help

Has anyone made a calculation for example, how much (or the mean) time it takes for an individual gas molecule to be displaced a distance of one meter (measured straight) from its original location? For example, air molecule at ambient pressure with a mean free path of 68 nm. That would be...
3. ### What branch of mathematics to study to understand Quantum Mechanics?

I just got a book on Quantum Mechanics, but at a loss with the maths. I had Algebra, Trigo, Calculus, differential equations, etc, but that was a long time ago, now as a programmer, I hardly ever think of those and forgotten them as a result. I believe I still have strong enough concept of...
4. ### Java Sample code/tutorial for simple, educational, physics java applets?

Something like this: http://www.falstad.com/vector/ Particularly concerned with particle motions. I don't know how to begin with using physics equations for creating simple java visual simulations. Can be 2D or 3D. I know some java programming so I'd prefer code examples than...
5. ### Maxwell's Demon via molecular reed valves can produce work?

Well not literally The Maxwell's Demon... If a one-way reed valve can be brought down to size of only a few molecules, don't you think it could allow passage of a gas molecule across a barrier in one direction only? How I think it could work: -The small size (molecular) of the valve is...
6. ### Does colder intake charge really work on Dyno?

Hello, I got a question on auto engines. especially on Naturally Aspirated engines. I know that colder intake = more oxygen in the mixture, then the ecu will compensate that with more fuel, etc, etc, more power... But colder air will also result to less efficient atomization of fuel...
7. ### Can I use 24 Volts input to a car ignition coil?

I'm feeding the current in pulses via 50v 6800 mfd capacitor. Will it destroy the ignition coil instantly, or will just overheat it? It won't be for automotive use but for general high voltage experiments. As long as instant destruction is a remote possibility, it's easy enough to mitigate...
8. ### Question on Expansion valves

For example in typical window-type home air conditioning: -If I remove the expansion valve and replace the valve with a small diameter tube to constrict the flow of gas so that the average gas pressure difference between the condenser and evaporator coils are the same as when you had...
9. ### Frames can really travel faster than light?

I've read about 'ergosphere' in wiki and surprised at the information presented that ergospheres around very fast spinning black holes can drag space time many times faster than light! Such that any object that falls into this spinning ergosphere, will also begin to 'accelerate' to match the...

What if I put a light object like a small paper boat in front of a large subwoofer and a loud sine wave was played, will that object move away from the sub woofer? Will the paper boat move away too if the above experiment was done in microgravity? The purpose of microgravity experiment is to...
11. ### Does light slow down (relativistic) near a black hole?

Does photons actually slow down near a black hole? Whenever I look up these info, I always read the mention of red shifting. The problem is we don't have a detector that is immune from the effects of relativity to directly observe these events in real time. However, does current...
12. ### If temperature gradients cause wind in air, how about in zero gravity?

If temperature gradients cause wind in air, how about in zero gravity?? Hey guys, I'm aware that atmospheric temperature gradients causes changes in bouyancy so hot air goes up and cold air goes down and immediately fills in the 'void' the hot air left, thus causing wind. What about in...
13. ### What is the mean molecular speed of Mercury Vapor at room temperature?

I have few questions regarding mercury vapor, except those related to health hazards. What is the mean molecular speed of mercury vapor at room temperature and speed of sound in a pure mercury vapor also at room temperature? Also, for the same density of air at seal level, can mercury...