Recent content by C. Darwin

Hmm, I don't really follow. Keeping the 100 MS/s and 8 bit res, let's say I have a channel from 110 MHz to 120 MHz (centered at 115 MHz). How does increasing the channel width affect the throughput, the resolution is still 8 bits...

I'm trying to get a basic understanding of RF DAC. If I have a DAC that does 100 MS/s with an 8 bit resolution, this translates to a 800 Mbps throughput. Or is this too simple? Now, how does the bandwith of a channel affect this? Say I have two 5 MHz channels. With two channels there...

Homework Statement \Psi(x,0) = \frac{1}{\sqrt{L}}, ~~~~~~ \left|x\right| < L/2 At the same instant, the momentum of the particle is measured, what are the possible values, and with what probability? Homework Equations The Attempt at a Solution Well, I know that \Delta{}x = L so can I then...

Thanks, I got it. Am I supposed to post a full solution?

By substiting x =a * tan(\theta) I was able to solve for \frac{C^2}{a^3} = \frac{2}{\pi} I now need to find the expectation values of x and x^2 I'm not sure how to get started (are they just zero? if I plot this function I get a curve peaked at x=0...)

Homework Statement \Psi(x) = \frac{C}{a^2 + x^2} Homework Equations I know to do this I need to solve for: \int_{-\infty}^{\infty} \left|\Psi(x)\right|^2 = 1 The Attempt at a Solution I'm not sure how to do it for this function. I've tried various methods to solve C^2...

Yes it is the number of modes per volume. I think one of the issues I was having with this problem was that I didn't realize the peak of the black body was supposed to be at 500 nm, and that the filter was centered at the peak.

Homework Statement In an experiment to measure photon statistics of thermal light, the radiation from a black-body source is filtered with an interference filter of bandwidth 0.1 nm centered at 500 nm, and allowed to fall on a photon-counting detector. Calculate the number of modes incident on...

The point of the problem is to use x and \dot{x} with the lagrangian and prove that the CM stays in place

All motion takes place in the vertical plane. Alpha is just the angle the rod is at when it's initially released. The end of the rod is touching, but NOT attached, to the ground. I specified the KE of the rod by the translational motion in the x direction and by the rotational motion...

Homework Statement I've got a rigid rod, length 2a, held at an angle \alpha above a smooth horizontal surface. Its end is in contact with the ground. My two generalized coordinates are x, the horizontal position of the center of the rod and \theta the angle between the rod and the vertical...

We're not adding angles though, we're adding radii. And since the problem spoke nothing of it, I'm certain this is an inertial reference frame.

Eh, actually I had a little typo last time, what I should have said was: I had previously thought that b\dot{\theta} = a \omega but it should actually be (a+b)\dot{\theta} = a \omega. So \omega^2 = (\frac{a+b}{a}\dot{\theta})^2 That being said, I still don't quite understand it. If you...

To the PF community: Is it customary for me to work out the correct solution to the problem and/or edit the information that was incorrect in my OP? Also, being that this was from a specific problem in a specific textbook, is there a proper way for me to indicate that? I think I've seen...

Ok, I solved my problem. I had previously thought that \dot{\theta}=\frac{b}{a}\omega but actually it should have been \dot{\theta}=\frac{a+b}{a}\omega. This lead to a lot of simplification... PS - chrisk Thanks for the link, but I think that analysis is way overly complicated. The system...