Recent content by i_hate_math

Thanks heaps!

The potential at the surface should be zero outside the surface since the total enclosed charge would be zero. Between the cathode and anode (outside the wire, inside the shell), the potential difference is: V = [Q/(2πϵL)]*log(b/a) where b=30mm and a=36.8μm => V/log(b/a) = [Q/(2πϵL)] So...

Let r = position of the electron = 6mm - 36.8μm; λ = mean free path traversed. Integrate E(r) = Q/(2πϵLr) between the two shells gives: V = [Q/(2πϵL)]*log(r/(r-λ)) I know that the question is asking for the voltage at which the electron energy will get to 23eV, but i am unsure how to get rid...

Homework Statement Consider a solution in which 99% of the atoms are 4He and 1% are 3He. Assuming that the 3He atoms behave as an ideal gas of spin-1/2 particles determine the Fermi energy of the 3He atoms. You may assume that one mole of 4He occupies a volume of 28 cm3.Homework Equations EF =...

Thanks for ur reply! I'm still a bit confused as to how this expression is obtained? I'm not too familiar with convolution, would u care to explain why the convolution is the same as f(a) in the limit t->0

Homework Statement Show that k(x,0)=δ(x). Where k(x,t) is the heat kernel and δ(x) is the Dirac Delta at x=0. Homework Equations k(x,t) = (1/Sqrt[4*π*D*t])*Exp[-x^2/(4*D*t)] The Attempt at a Solution I am just clueless from the beginning. I am guessing this is got to do with convolution...

No I haven't. This was a question in a past exam that I'm stuck on, it could be unrelated. Was I right to consider it as a purely thermodynamic (2nd year physics level) problem?

Does a system with zero entropy represent the thermal equilibrium at some temperature = 0K? Does the second law of thermodynamics entail that the system will eventually evolve to higher entropy? e.g. a system of 7 magnetic dipoles of paramagnetic spin-1/2 particles in an external magnetic...

The enthalpies of formation with reference to (2) are: ∆(Glucose)= −1,268 /, ∆(Carbon Dioxide)= −393.5 ./, ∆(water)= −285.8 /. How do I calculate the enthalpy for the combustion of 1 mole of glucose? I know H = U + PV and ∆H = Q + Wother, but I am confused by all the chemistry involved!

Thanks!

Thanks!

Thanks very much for your reply. I've not learned in great details parity and eigenstates, but I get the main idea.

In 1D QM: I understand that if a given potential well, U(x), is symmetric about x = L, then the expectation value for operator [x] would be <x> = L. (I am not even entirely sure why this is, guessing that the region where x<L and x>L are equally probable) Is it possible to draw conclusion...

Thanks for your reply! I am still a bit confused by how exactly motion changes the labelling of the 'now'? Is it because with relative motion to initial/rest position, one can reach the information/photons earlier or later than rest position? If so, does the distance between the observer and the...

Even though, I'm more attracted to the physics now than finishing my philosophy assignment. Please give us some hints on how to approach this interpretation