Recent content by user3

Imagine that there's air in space, and that on Earth there's a very famous hungry toddler that produces a very loud scream every 1 hour when it's hungry. The screams of the baby are your wave crests. Now, a few planetary systems away there's an alien trying to get some sleep after a long work...

Thank you all.

But I already understand that. What I was asking was why the Doppler shift for sound doesn't depend only of the relative velocity only (like the relativistic Doppler shift). But I think I got it now. The speed of the light is same in every frame of reference, while the speed of sound is not.

you mean that what makes the difference is that when the source is moving the wave crest really are compressed, while when the observer is moving he's just moving through them faster(they are not compressed) ?

I have come to learn that the Doppler shift equation is asymmetric. That is, the Doppler shift is not the same when source is moving towards the observer or when the observer is moving towards the observer (both with same speed). I have looked at the derivation of the Doppler shift equation...

Since the Maximum Intensity of the wave is just the Amplitude squared: I=|A|^2 , we can deduce that the amplitude of the wave coming out of one speaker is ##\sqrt{15m}##. We also know that the Total Maximum Intensity (I say maximum because we know the in the middle -along the x-axis- there's...

As b→a, the transcendental equation becomes \frac{-k}{\sqrt{z_0 - k^2}} \frac{2e^{2ka}}{0} = tan(a \sqrt{z_0-k^2}) I can't see any other 0's.

Yes That's what I expected. I even solved the problem of the Well where the limit has already been taken and It gave me multiple solutions, like expected. I am sorry, I just realized that I have been taking the limit incorrectly. I now realize the I have a division by 0 when I take the limit...

Yes that's true. I was looking for the E<0 solutions. Only the even solutions also. Here's how I solved it: \psi(x) = C sin(lx) + Dcos(lx)\:\:\:\:\: 0<x<b \:\:\:\:\:[1] Note: l = \frac{\sqrt{2m(E+V_0)}}{\hbar} \psi(x) = Ae^{-kx} + Be^{kx}\:\:\:\:\:b<x<a \:\:\:\:\:[2] since...

The r can be the distance from any of the three speakers since L >> a. Imagine standing 1 Km away from 3 water bottles separated by 1 cm. The distance between you an any of the bottles is practically the same. An order of magnitude is the power of 10. It just means the distances are almost...

Ok here's a potential I invented and am trying to solve: V = -Vo in -b<x<b and 0 in -a<x<-b , b<x<a where b<a and ∞ everywhere elseI solved it twice and I got the same nonsensical transcendental equation for the allowed energies: \frac{-k}{\sqrt{z_0 - k^2}} \frac{e^{2kb} +...

just added the steps

I am working on the Hydrogen atom and I was trying to calculate \frac{d<r>}{dt} using \frac{d<r>}{dt} = \frac{i}{\hbar} <[\hat{H} , \hat{r}]>. Here r = \sqrt(x^2 + y^2 + z^2) and H = \frac{p^2}{2m} + V where p^2 = -\hbar^2 \nabla^2 . Now according to Ehrenfest's theorem <r> should behave...

It's the first time that I have been told that. How is that? What about this E = h f ? Please elaborate

I did not say shorter time intervals produce shorter wavelengths. Instead, I said it they will produce fractions of a wavelength.