Recent content by Mr LoganC

Homework Statement COnsider electrons tunnelling through a 10eV barrier over a distance 0.001mm. Find E_{1}. (The energy of the first tunnelling resonance.) Homework Equations I have an equation for the tunnelling probability...

Ohhh... and of course I'm calculating it for a "Free" atom, not one bound in a solid! So the higher velocity makes sense! Thank you so much for the help!

Homework Statement Calculate the Doppler velocity needed to compensate for the recoil energy. Homework Equations V=\frac{E_{0}}{m c} The Attempt at a Solution I found the recoil energy to be 1.95\times10^{-3} eV. And for Iron-57, E_{\gamma} is 14.4KeV. Which is approximatly equal to...

Actually, that IS the problem! I think you are correct, Bloby. Because the Plank constant is squared on the top, so there is still another 1.6x10^-19 to factor in there! I will give it a shot and see what I get for an answer! **** It Worked! Thank you Bloby! Final answer was 16nK, which seems...

But since the plank constant is on the top and Boltzman on the bottom, the converting factor of eV to joules (1.6x10^-19) would cancel out anyway, so whether it's in eV or Joules should not matter.

This isn't true though. From the definition, it's the change in θ with respect to time. So it doesn't matter how far away the sun is, the angle θ is still changing at the same speed independent of the radius. It's true that the velocity of the sun would be different at the top of the tree and...

Homework Statement Estimate the Bose-Einstein condensation temperature of Rb 87 atoms with density of 10^11 atoms per cm^3. Homework Equations T=\frac{n^{2/3}h^{2}}{3mK_{B}} The Attempt at a Solution This should be just a standard plug and chug question, but my answers are not...

Nothing I guess. I'm a terribly slow test writer, so perhaps I'll leave that one 'till the end, but at least I can show my work and show that I do know how to go about the problem! Thanks again Tiny-Tim! A thumbs up to you, sir!:biggrin: -LoganC

So if this question were to show up on the exam, (This is a practice question from last years exam), How should I go about doing it? And I still have to use spherical coordinates!

So I worked through the problem and got an answer. Took me a good 30-40mins. There's no way he would give us one question that takes 40mins to do on the final. So I must have either done something wrong or did it a very difficult way. Not only that, the integrals were very difficult! I ended up...

Rightttt! It's been a while since doing spherical! So I need to convert those. Also, does it matter which I change from 2pi to pi? Forgot about that too, having both at 2pi is just like sweeping it out twice. So should I only let phi go from 0-pi, or does it not matter which one I choose...

Okay, well then I'm confused again, because I would have this: (Using Spherical coordinates) M=\int_{\phi=0}^{2\pi} \int_{\theta=0}^{2\pi} \int_{r=0}^{1} (x^{2}+y+z)r^{2}sin\theta dr d\theta d\phi But if I'm only integrating with respect to radius, theta and phi, then the x, y, and z would...

This is just a practice problem, not actual homework. I'm studying for my final but am having a bit of difficulty in understanding this concept. Homework Statement Consider a solid of non-uniform density ρ=x2+y+z, consisting of all points inside the sphere x2+y2+z2=1 a) Find the mass of the...

Oh right! I forgot about the whole "Only boxes 2 & 3 together" thing! So in that case I tried N, N, N, A, N. Meaning the only force present on the diagram was the force of the floor pushing on box 2 in the vertical (A) direction. And it worked! That was the solution! So thank you very...

In that case, I would get N,B,N,A,A which also was not correct. And in the case that neither of the last two (floor pushing on them) are part of the FBD, because the floor itself is not in the diagram, I also tried N,B,N,N,N which didn't work. Is that what you would have gotten also? Perhaps...