Recent content by fricke

How can I prove that the entropy change is intrinsically positive? Given two systems with both of the heat capacities are independent of temperature.

I am really stuck at this question. I tried to get the equation of volume with independent variables P and T, but the equation itself does not give a nice form, and thus I cannot get the derivative of V with respect to P. What should I do?

I completely have no idea what time-reversal mean. Why does, by substituting -t into an equation and if the result is the same as the original equation, then the equation is said to be time-reversal symmetry? Also, what does that 'symmetry' mean there? An even function?

Thermodynamics question: Why does the internal energy have a lower bound? I tried to explain it using postulates, but cannot get the connection between the postulates. Please do explain it briefly. Thank you.

Hmm.. I don't get why the proof starts with that |Z> Mind to explain it, please? thanks :)

Why is there no Coulomb's Law for the electric displacement?

In what condition(s) curl of electric displacement is zero? Is it okay to say curl of electric displacement is zero in: 1) in electrostatics (curl of E is zero) then followed by the following conditions: 2) when there is no polarization (curl of P is zero) 3) in uniform polarization (which...

What's the line integral of sphere? Is it possible to get the line integral in three dimensions? What kind of line are we integrating?

No, I haven't learned that theorem yet.

if you pull a loop of wire (to the right) with velocity v and charge is moving perpendicular to your motion (upright) with velocity u, so which velocity does the magnetic force refer to? the loop of wire is immersed in an uniform magnetic field (toward the page)

Why magnetic field never do work?

Not a homework question! I am doing exercises for upcoming final exam. So, I get stuck at question 5.27 (Griffith 4th edition textbook). Question: Find the vector potential above and below an infinite uniform surface current with constant current sheet, K flowing at positive x direction. I...

thank you. I have found out a really easy way to construct Slater determinant for electron spin of an atom :D

thank you! I have another question. Prof taught us one row represents one electron, so each electron is represented in a row in Slater Determinant. But when I googled it, some represents one electron in one column (not in one row!). Mathematically, it seems to be not wrong (since I didn't do...

I understand how to calculate the determinant. But how to construct determinant for electrons spin in an atom?