Recent content by tarkin

Homework Statement [/B] For the first excited state of a Q.H.O., what is the probability of finding the particle in -0.2 < x < 0.2 Homework Equations Wavefunction for first excited state: Ψ= (√2) y e-y2/2 where: The Attempt at a Solution To find the probability, I tried the integral of...

Homework Statement Show that the mean value of a time-independent operator over an energy eigenstate is constant in time. Homework Equations Ehrenfest theorem The Attempt at a Solution I get most of it, I'm just wondering how to say/show that this operator will commute with the Hamiltonian...

Homework Statement [/B] Consider an electron beam traveling with velocity v. The total current of the beam is I.The beam is of uniform charge density and has radius R. (a) Find E and B at r<R and r>R using Gauss' and Ampere's laws. ( This part is fine.) (b) Consider an electron in the beam at...

I keep getting confused with E and D, in electrostatics, and B and H, in magnetostatics. I've done some reading around, but some people seem to say the opposite of others. I was hoping someone could clarify for me once and for all! So, my thinking was that, E is the total electric field, due to...

Hi, sorry, I should probably have said a bit more in my OP. Presumably, in the question, the 2 particles are indistinguishable. So it means that eigenfunction must be antisymmetric under particle exchange. ie. that if the particles are swapped, this will give the negative of the original...

Homework Statement [/B] By considering the eigenfunctions for 2 noninteracting particles at distances r1 and r2, show that their total eigenfunction must be antisymmetric. . Homework Equations Spatial wavefunctions: Ψ(x1,x2) = 1/√2 [ ψA(x1)ψB(x2) ± ψA(x2)ψB(x1)] Where + gives a symmetric...

Okay, thank you!

Homework Statement [/B] Derive expressions for the magnitude and direction of the electric field at point P and the potential at R. Charges Q1 and Q2 are both positive. Distance from Q1 to P is h, distance from Q2 to P is √2 h Homework Equations E = k q/r^2 The Attempt at a Solution I...

Okay, I'll take another look at my working out. Thanks a million!

When I subbed in k I hoped the m's would cancel but I couldn't get them to. Is it just some mistake I'm making - should they indeed cancel? Thanks

Homework Statement Please see attached image. I'm trying to do part (d), then (e) afterwards. For (d) I can sketch the graph okay, just trying to calculate T now. Homework Equations T= 4k1k2/(k1+k2)2 k = ((2m/ћ)2(E-V))½ The Attempt at a Solution I tried substituting in k into the equation...

Thanks guys, it was Kepler's 3rd that I needed.

Homework Statement http://prntscr.com/dsd7ea Image attached Homework Equations For circular orbit, r = Pv / 2 pi , Where P = orbital period and v=orbital velocity r' = r sini , where i is unknown angle to plane of sky.The Attempt at a Solution [/B] I'm really not getting these binary...

Thanks Evo!

How's it going folks?