Recent content by 0ddbio

This is actually a GRE problem, I'm just trying to go through and understand them all for studying purposes, but I don't understand how to do this one at all. Homework Statement A student makes 10 one-second measurements of the disintegration of a sample of long-lived radioactive isotope and...

ooh, yes of course! thank you both very much.

Thanks for the response. I am so sorry, I mentioned the wrong portion of it. I meant to say that about going from the first expression on the middle line to the second. There was no \langle x|p\rangle I'll just rewrite it here for your convenience. The part I was referring to was this...

I am confused about two minor things right now. The following illustrates both which I pulled from my QM book: <x|p_{op}|0>=\int_{-\infty}^{\infty}dp<x|p_{op}|p><p|0>=\int_{-\infty}^{\infty}dp~p<x|p><p|0>...

Where did you get that problem from? There is a misconception in it I think... if I try and figure out what it is supposed to be, there is like 5 different possibilities. The problem is that force vectors are supposed to be drawn like this...

Ya that does help a lot thanks. Although I did get that the momentum operator in momentum space is just p directly from the book. It's just like in, say 1 dimension, the operator \hat{x}=x like if you want to find the expectation value of the position you just put "x" as the operator which goes...

Awesome guys, thanks! Perhaps you could answer another question so that I don't have to start a new thread. The motivation for me starting this thread was that the book is going over eigenvalue problems and for instance this one: \hat{H}\psi(x)=E\psi(x) makes perfect sense, however the other...

Schrödinger Equation in momentum space? ?? I don't know if this makes any sense at all, but I'm studying QM and just trying to generalize some things I'm learning. Please let me know where I go wrong.. Basically by my understanding the most general form of the Schrödinger Equation can be...

Mechanical energy is a conserved quantity. Unless things like friction are involved (non conservative forces) but the problem would state this outright. Therefore the mechanical energy at the bottom of the slide is the same as the top. You are using the KE at the top of the slide plus the PE...

Well every textbook I have seen it in says that it is: \frac{\hbar}{2} which is equivalent to: \frac{h}{4\pi} Perhaps others could shed some light on why you may see it displayed different ways in different situations... But, as far as I know this is the actual formula. and it is really the...

You are doing it right, you are just getting rounding errors I believe. Try writing it all out into one big equation. without substituting any numbers. Then just put all of the numbers in at the same time for one calculation at the end, this will be more accurate. I just did it the same way you...

There should only be a single acceleration graph.. unless there are other forces acting on the block other than gravity. The gravitational acceleration on the block does not care if the block is going up or down, the acceleration is constant. Therefore the acceleration-time graph is just a...

I could generate two identical velocity-time and acceleration-time graphs, for two different situations with different ramp angles and different coefficients of friction.

You are trying to use the instantaneous velocity as if it were an angular quantity. When working with speeds of things rotating or traveling in circles, what you want is the angular velocity \omega. So find out how to find what the angular velocity is given the instantaneous velocity.

You would need at least some kind of additional information. Even if there are no external forces but gravity on the block, and your acceleration-time graph is just a constant you would still be unable to find the coefficient of friction without at least knowing the angle the ramp makes with...