Recent content by Guidenable

Found it. The energy of the photon isn't delta(m)c^2 as the atom is moving. So in the atom's frame, the photon is redshifted. The energy of the photon (which is hf in a rest frame) is now hf', where f' is the shifted frequency due to the transverse relativistic doppler effect.

Homework Statement An atom of mass M decays from an excited state to the ground state with a change in mass of ΔM<<M. In the decay process, the atom releases a photon. Use the laws of energy and momentum to determine the energy of the photon, assuming the atom decays from rest. Homework...

Yes, I understand now, thank you very much!

So I just evaluate the integral?

Thanks for the correction, I normally know log rules, just that one slipped. You guys mean bringing the log into the sum, right?

Never mind. Those two series are related by a factor of 1/zn. I should have looked a bit closer :/.

No, but now I intend to find out. A hint would be appreciated though.

Homework Statement Find the exact sum of: \sum 2/(n7n) n=1->∞ The Attempt at a Solution Let Sn denote the nth partial sum. ln(Sn) = \Sigma ln(2/(n7n)) =\Sigma ln2 - lnn - nln7 = nln2 - (ln1 + ln7 + ln2 + 2ln7 + ln3 + 3ln7 ...) = nln2 - ln(n!) - ln7\Sigma n = ln (2n)/n...

I think so too. The limit of xn/n! as n--->0 is 1, not 0 as x0=1 and 0!=1. As for xn/n! as n--->∞, try expanding the numerator and denominator of the limit. What does xn look like? What does n! look like?

Ah ok, it's quite possible that the prof mentioned it but I missed it. Thanks for the link, I'll put it to good use.

I've never heard of eigenvalues or eigenvectors. I'm in a college level Linear Algebra I class, so I don't know if I should or not.

Homework Statement Given the matrix A= -1/5 7/5 -3/5 -4/5 find A43. The Attempt at a Solution It's obvious that I can't go and actually compute A43 so there must be a more elegant way of doing this. The only notes I have on the subject is Ak=P-1DkP, where D is a diagonal...

"I have no idea what you mean by "matrix A= [u,v]" nor in what sense it "represents V". You can't make a 4 by 4 matrix from 2 vectors and a matrix does not "represent" a subspace." What I meant was that if you took A= [u,v] and then said that Ax=z, where x is any vector in R2, then you have in...

Homework Statement Let u=(-1,-2,-2,2) and v=(-1,-2,-2,-1) and let V=span{u,v}. (Just to be clear, u and v are column vectors) Find the standard matrix that projects points (orthogonally) onto V.Homework Equations The Attempt at a Solution I started by making a matrix A=[u,v], which...

Oh wow. Thanks a bunch, can't believe I didn't see that XD