# Recent content by thatguy14

1. ### Fourier Properties (shifting)

Hi, I need help with some basic fourier transform properties stuff - its fairly simple though I think I am doing something wrong. So we know from the shifting property if h(x) has the fourier transform H(f) then h(x-a) has the fourier transform H(f)ei*2*π*f*a so I have the function cos(2πf0x...
2. ### Wave function at infinity

Okay thank you. I think it is sufficient for my course. I appreciate your time!
3. ### Wave function at infinity

I think I see what you are saying. I will give a little more information into what I am trying to do. The question is: Consider two normalizable wave functions Ψ1(x, t) and Ψ2(x, t), both of which are solutions of the time-dependent Schrodinger equation. Assume that the potential function is...
4. ### Wave function at infinity

We aren't given any. Some other information which might be helpful though, the wave function is normalized, it is a solution to the time dependent schrodinger equation and the potential function is real. And again it approaches zero as x goes to +- infinity. Is that enough?
5. ### Wave function at infinity

Homework Statement If I have a wave function that goes to infinity can I assume that the derivative also goes to 0 at infinity? Homework Equations The Attempt at a Solution The reason I think it does is because the wavefunction and its derivative must be continuous everywhere...
6. ### Average energy mass on a spring

ah okay thanks!
7. ### Average energy mass on a spring

Homework Statement Hi, I hope this isn't a silly question. I am looking to find the mean potential energy of a mass on a spring with spring constant k and maximum displacement x0. Homework Equations The Attempt at a Solution I know the maximum energy is 1/2*kx0^2 so would the...
8. ### Quantum well combination

I did some work on c, hopefully someone can give me a reply to this to make sure I am on the right path. so I said that the solution is similar to the finite potential well. In region A which is between -b and -a the wavefunction is of the form: \psi = Aexp(kx) + Bexp(-kx) (I know that...
9. ### Quantum well combination

Can anyone help please? If I am being unclear please let me know
10. ### Quantum well combination

Homework Statement The question is attached as a picture. Note: if someone would prefer I type it out I can. Homework Equations Schrodingers equation The Attempt at a Solution PART A I am pretty sure I got the well right. It looks like a finite well inside an infinite well. I...
11. ### Stirlings approx/CoinFlips/Gamma function

Please ignore number two, it required that the terms left off to be added. Still need help with 1 and 3
12. ### Stirlings approx/CoinFlips/Gamma function

Homework Statement Hi I actually have three questions that I am posting here, help in all of them would be greatly appreciated! 1) Prove that ln(n!) ≈ nln(n)-n+ln(2*pi*n)/2 for large n 2)Supposed you flip 1000 coins, what is the probability of getting exactly 500 heads 3) Show that n! =...
13. ### Estimate energy of infinite well (ground state)

Homework Statement We have to estimate the ground state energy of an infinite potential well (1d) using an argument based on the heisenberg uncertainty principal. We then are supposed to compare it with the exact value from the eigenvalue equation. Homework Equations Below The...
14. ### Planck Black-Body Law

Homework Statement Starting from the Planck-Body Law I_{λ}dλ = \frac{2\pi c^{2}h}{λ^{5}} \frac{1}{e^{hc/(λkT)} - 1}dλ where λ is the wavelength, c is the speed of light in a vaccuum, T is the temperature, k is Boltzmann’s constant, and h is Planck’s constant, prove that the total energy...
15. ### Free Current

I mostly understand that. The answer the book gives for I free is = (I*pi*s^2)/(pi*R^2) which makes sense, but I am looking for what definition they used exactly to get that. What equation?