Recent content by PatF

Homework Statement This is a question from an old exam. The answer I have is marked wrong but I do not know why. A conducting sphere of radius a is at potential V and sits at the center of a conducting spherical shell so large that it can be considered infinite and whose potential is...

Thanks much! I just checked and I think you are right.

In Reif's book Fundamentals of Statistical and Thermal Physics, he labels two formulas as the Stefan-Boltzmann Law. They are both involve T^4 but the constant is different. In one, on page 376, the law is given as (pi2/15)*(kT)4/(c*hbar)3. The other, on page 388, is...

I am taking a course in statistical physics where we keep using the terms in the title. I think I understand them as stand alone terms, but I do not understand any relationships. For example, does quasi-static and reversible imply adiabatic? Does one of them imply some of the others? What...

This is a question, I think, of "unknown unknowns." I know I don't understand something but I am not quite sure what I don't understand and I am trying to work through it. So... 1) I have been following some of the threads about current in wires and electrical fields and, if I understand...

OK. I think I have it now and I will write down the solution in case anyone else runs into the problem. I think the problem is lot subtler than it looks and the key is figuring out what it doesn't ask for as much as figuring out what it does. So... First, picture the wheel as rotating...

"Think about the physical meaning of the phrases "rolls without slipping". What does this imply is the relationship between rotational and translational velocity?" I am terribly sorry but I HAVE thought about this but it seems absolutely pointless. You might as well say that I should...

Homework Statement A wheel with rotational inertia I = 0.5MR^2 about its central axle is set spinning with initial angular speed w and is then lowered onto the ground so that it touches the ground with no horizontal speed. Initially it slips, but then begins to move forward and eventually...

This is, I think, called the localization of the integers at the prime p. It really consists of all rational numbers whose denominator is not divisible by p. So, what does an element look like when it is not invertible? (I think you already know about them.) Pick a prime, say 5, and look...

Homework Statement This is a problem that was on a quiz. The quiz has already been graded and handed back and the faculty member graded very gently. (This means I passed when I think should not have.) I have thought about the answer I gave at the time and it was pretty bad. My current...

"T= (x-bar - mu initial)/(s/ sqr n) Now, what If i have no mu initial given. . . Example- Sample mean= 0.8 St. D= 0.1789 n=6" In this case, I think what you want to do is _find_ mu initial. So, plug the values you have into the above formula. This gives, T=(.8 - mu...

Naresh "3) The definition of eV is that it is the energy acquired by an electron when accelerated through a potential of 1 V (hence electron-volt). In the Franck-Hertz experiment, you accelerate electrons through some voltage, say 4.9 V. Therefore the electrons would have energy ___ eV?"...

I am not sure if this is the right place to post this so sorry if it is wrong. Be that as it may... I have just completed a lab in which we do the Franck-Hertz experiment. I am trying to understand it so I have a couple of questions I hope you can help with. 1) There is an oven into...

I have seen this called Eilenberg's trick. The idea is that Q+P=F1 where Q is projective and F1 is free. Now let F=F1+F1+F1.. a countable number of times. Then, P+F is isomorphic to P+Q+P+Q+P+Q.. which is isomorphic to F.

I have run across two formulas for Planck's Law of Radiated Power Density. According to http://hyperphysics.phy-astr.gsu.edu/hbase/bbrc.html#c1" it is Bf(T)=((2*pi*h*c^2)/(lambda^5))(1/(e^(h*c/lambda*k*T)-1)) However, in one of your forums, the pi is missing as it is here...