NeonBlack

[math]KE=1.6\cdot10^{-19}C \cdot 10000V=1.6\cdot10^{-15}J[/math] Calculate the speed from the kinetic energy. Calculating electric field can be complicated. In general, [math]\vec{E}=\vec{\bigtriangledown}V[/math] This probably isn't going to help you. If we assume that the potential is created from two (relatively) large parallel plates, then the electric field is a constant, [math]E=V/d[/math], where d is the distance between the plates.

You probably need to look inside for the accelerating voltage, which will typically be 10000 volts or higher. Then you know the kinetic energy will be [math]E=eV[/math], where e is the electron charge. Now, calculate the speed.

Yes, John is absolutely correct. I'm sorry I don't know what I was thinking when I said that. Electrons are a major constituent of the solar wind, so yes, I would say that an electron gun could be used to simulate part of the radiation astronauts would experience.

short answer: A phosphor is basically something that lights up when an electron hits it. You can use it as an electron detector. http://en.wikipedia.org/wiki/Phosphor A television repair shop should be able to hook you up with an electron gun, although these are becoming rarer as more people just throw away their old/broken tv's.

Maybe you could get an electron gun with a phosphor screen. Although electrons at these energies are not ionizing, it would be much safer than using radioactive sources or trying to take apart a microwave. (Not to mention a magnetic field won't do anything to microwave, uv or gamma radiation). Also this has the benefit of being able to see the particles. Close to the earth, the magnetosphere approximates a dipole, so a small bar magnet should be fine.

They pay us to leave? Seems to me to be the obvious solution.

One time my grandpa tried to knock down a bee hive outside his house with a baseball bat. For the next few days, he didn't complain at all about his arthritis.

Somehow, I'm not surprised.

ajb, did you mean the phase velocity can be greater than c?

Nice watch!

Heap variables are initialized to 0, stack variables contain garbage. The unwritten rules of c++ say that a variable should be declared just prior to its first use, so most of the time, you should initialize variables. You can just post your entire code and say "fix it." You need to say which parts are giving you trouble. If you're getting compiler errors, post them. If you have bugs, say what you expect vs. what you're getting. If there's something you don't understand, post a small example.

We already do that. It's called wind. Actually I would not be surprised at all if UFOs were powered by wind. That's probably not what you had in mind. Some submarines are powers by the temperature difference between the cold ocean water and a hot hunk of radioactive crap. I think the problem of trying to use this on a large scale is that it's not easy to find a huge temperature gradient over a reasonable distance.

Talk to your adviser or junior/senior students. They should have a pretty good idea of what the courses are like. Most of the time, if you need math beyond the 4 semesters of calculus, you will learn it "as you go," that is, maybe in your physics course you will spend a few days learning the math before you need it.

CRYSTALS have amazing healing powers.

Does it happen with messenger? browser client? both?

Those were jokes, by the way. I have gotten most of them. Sorry if that was too subtle.

This thing must be broken. I'm certain that these are correct, but it isn't counting them: 18 H on a G C: 18 Hands on a Grandfather Clock 5 T on a F: 5 Tires on a Five-wheeler 15 P in a R T: 15 People in a Rummy Tournament 13 L in a B D: 13 Letters in a "Bad Dictionary" 13 is U F S: 13 is an Unlucky Friday (Superstitiously)

Well, why can't it be both? It sounds interesting. I will have some time to watch it tomorrow evening.

Many years ago, my uncle drove a Chevy Nova. I have to say it was definitely NOT the car of the future.

But, but, but... ... F*** BUSH!

"Back" to when? He's in office today!

Darkshade's first equation is for ELECTRIC FIELD, which isn't really relevant, and it only applies in some special cases, it is not true in general. For a coiled electromagnet, the quantity affecting the strength of the magnet is current, regardless of voltage.

I take it you gave up on your old one with the cooling issues? I don't know about the newest models, but Toshiba lappies are known to have issues. I have one with a huge heat sink and another whose fan runs almost continuously. Since it's for your sister starting college, I'm guessing the primary uses are going to be e-mail, facebook, ms word and music/video storage. If this is the case, I would say your priorities would be 1. price 2. mobility 3. power (as long as you get a decent hard drive if using it to download)

iNow, I know that's what atheism is in principle, but I think in practice, it is becoming an institution. It's just my opinion, but I feel that it's best to avoid these discussions altogether.

So far, the suggestions have been pretty absurd. Throw the money into a jar, fill it up with clear glue or silicone.