Physics

I have decided not to do something with ice sampling- too hard, and too many variables. Instead I have decided to do an experiment with propellers. Does anyone know a good website with strong background info on propellers, that is somewhat dummy proof? Thanks!!!!

Is inertia a force?

I understand to overcome static friction..you must have an unbalance force more than the friction itself after you overcome static it changes to kinetic. Where does the static friction go? I understand it changes but can someone help me try to understand this a little bit better?

Ok, so my co-worker asked what the temperature of a photon was. Obviously, I have no earthly idea and had never pondered that before. Do photons have a temperature? And does it change with the wave-length?

need a bit of help till i turn in my paper.

AN oxygen atom is four times as massive as a helium atom. In an expriment of helium atom and an oxygen atom have the same kinetic energy. WHat is ratio V(He)/V(o) of their speed?

I have a science fair coming up for school, and while I have been doing a ton of research, I have a few questions. I am attempting to recreate an experiment in which a supercondcutor levitates back and forth along a track of permanent magnets. The track consists of 23 magnets, 3 magnets to a row, 7 magnets long, and 2 magnets laying perpendicular to the track. The experiment I am attempting to recreate is shown here at 3:52 The project even comes with very specific instructions shown here http://arxiv.org/PS_cache/arxiv/pdf/0803/0803.3090v1.pdf The instructions specify that a (3 cm hexagonal) enhanced flux pinning YBCO superconductor was used. My problem is…

Hi, im new to the forum and need some help with a project im attempting. My hobby is target shooting with air rifles and i have been playing around with a C02 powered gun. The problem with C02 as a power source is it is temperature unstable and will give varying power outputs depending on the outside temperature. My idea is to keep the C02 receiver at a constant 20 odd deg which seems to be a good average temperature the gun works at by using a heating coil powered by a rechargeable battery which i can hide in the wooden stock. The battery would be switchable and as an average competition lasts around 45mins i could turn the heater on 10 mins before the start and then of…

So, yesterday I was listening to a presentation given by a graduate student in a lab I work at. She was giving the presentation using power point and a projector. The lights were off, and I noticed something I have never noticed. When I would quickly glance at the beam of light being emitted from the projector, and glance away just as quickly, I would see the individual colors of light, almost in a rainbow pattern. The key is, this would only happen when I would look at the light for just a split second. It would also work if I looked at the beam of light and closed my eyes, and then open and shut my eyes as fast as I could. It was like when light travels through a p…

according to newton gravity is an attractive force.in that case earth should be attracted towards sun isn't? This maybe silly but a small doubt

ok, im just hypothesising here, but if you were to create an vehicle which has a very strong positive charge on its base (with a van de graaf generator perhaps) and devices all around the edges somehow fired a stream of postive ions at the ground around it (in the same way that an antistatic gun does onto a record) in order to make the ground positivley charged all around it. Could you make the vehicle levitate and make it fly in one direction by reducing the amount of positive ions fired at the ground in that direction? I just thought it might work since the charges in the vehicle base and the ground would repel each other since they are alike. feel free to dis this ide…

If you can think of certain aspects of relativity as rotating space into time then presumably you can draw a circle in time on one axis and space on the other and work out how many seconds are there in a centimeter?

I am a sales of Alnico factory in China,these days ,a customer visited us,they manufacture microphone,they want to purchase some Alnico magnets used in their microphone. I think about it,that why Alnico can make the voice better than other magnets,such as Neodymium.If anyone can give me your opinion I will appreciate. As I know that Neodymium's magnetic values are stronger than Alnico.and do their work temperature is just lower than 150-200C.and Alnico really have best stable magentic performance and temperature stability,but Microphone will not change a lot on temperature as I think.So what made Alnico better than Neodymium on performance of microphone. Thanks

This is a very serious question for all of you nerds. Who ever can answer it is the smartest nerd of all nerd. If i dig a hole through the Earth (from one end to another), then if i jump through it, will i fall out the other side or what? Because when i jump in it i will be falling DOWN but how could i come out the other side falling DOWN. Thats impossible. Someone please answer this question.

What exactly is time? The International System of Units (SI) defines the second as 9,192,631,770 cycles of the radiation, which corresponds to the transition between two hyperfine energy levels of the ground state of the 133Cs atom. ^taken from wikipedia^ Is there really such thing as time or is it just something we put in place of something we do not know how to answer?

I'm not even sure if this is where this thread belongs, but here goes. A few months ago I baught a Neodium manget. Worked great when I got it, really strong, but now, it can barely lift a pound where as before it could lift 80! I think I remember reading somewhere that magnets lose their power over time? Is there any way that I can recharge my magnet? Its just a cylindrical neodium manget about 2" tall and 1" diameter. I won't pretend to know what I'm talking about though.

I cannot remember there is a blue -blood princess who is just 12-year-old. She likes to kill people but not she nerve kills them herself. She almost keeps out of it. CSI can do nothing with her… Then I bought another dvd LV. There is also a 12-year-old girl. She helps her brother to escape from legal sanction, but then she kills another man to set a cunning trap for her brother. The police also cannot do anything to her. Which girl is more smart??

Hello! Gotta question here about Circular Motion... we all know that a = (v ^ 2) / r f = 1 / T and F = ma... Then how do I know which formula to use? For example, Calculate the force of gravity on a spacecraft 12,800km (2 earth radii) above the Earth's Surface if the mass is 1400kg?

I know an AC current can be rectified to a DC current with a diode bridge, but does the magnitude of the voltage and/or current change? If so, how. For example, if one had an AC current at 2 A and 12 V, and one converted it to DC, what would the current and voltage of the new DC current be? Btw, let's assume that the process is 100% efficient.

Hey guys! I think this topic belongs here anyway..but please bare with me if it doesn't As you can see, this topic is about the big bang theory. At school I'm currently doing coursework in Physics. At the moment our latest piece of coursework is to find out about the big bang theory, write down the big bang theory and back it up with scientific evidence. At the moment I;m very stuck with it all. about writing down the big bang theory. I don't know exactly what to write down? And scientific evideence. I don't know where I am supposed to find scientific evidence on the net. Is anybody willing to help?

Depending on how you define friction something could arguably never be frictionless. However one could create a gear that removed contact friction other than between a solid and air magnetically. Take a diamagnetic block of material with a cylindrical fixed magnet some distance above it, between these two items are a 2nd this time optional fixed diamagnetic block and a cylindrical floating magnet. The floating magnet is delicate, you could probably bend down to inspect it and breath on it too heavily knocking it off onto the magnet above or out of the edge of the experiment. However if careful one could get the floating magnet to levitate and spin slowly loosing speed…

Hi Id like to know how to work out what the maximum amount of gas i can get down a pipe is. The gas is methane. Its composition is roughly ch4 @ 59.5%, co2 @40%, 02 @ trace, h2o @0.5%, Nox & Sox = Trace, HCL = Trace. It is biogas and the temperature is around 34 C entering the pipework and 6 C before use. The Pipework is various diameters but it has a bottleneck minimum of 6" The pressure at the start of the system is around 15mBar / 150mm water gauge. The pressure varies across the system with diameter. Thanks for your help

Is it possible to trap light forever via mirrors? see example: So if I was to turn off the laser gun would the laser beam inside remain?

BTW, D H, I know I'm a puny undergrad, but this is really interesting; we just learned in class something about distribution of mass (and charge, they seem to have the same general concept). The professor didn't get into it too much but he did say that dipole moment (quadruple moment, etc) define the general shape and 'distortion' of the mass. Is that what you are talking about (simply, of course, I'm sure its a lot more complicated than that) ? btw.. hairy mathematics or hairy mathematicians? .. both can.. be.. uh.. challenging.

Hello. This is my first post ever here, and I'm pretty sure it's not in the correct section, and I apologize for that. So the atoms in a molecule vibrate in relation to each other. And when IR radiation is absorbed by a molecule these vibrations increase. Apparently absorption only happens if there is a change in dipole moment. How do the streching and bending effects change dipole moment? Is it that streching adjusts the distance between the atoms or what?