Recent content by bumclouds

And how long would it take to run out of oxygen? I often wonder if there's a tiny little gap of say, 1 square cm to the outside world, would you rate of oxygen consumption beat the inflow of oxygen?

I have a stupid question to ask you all. Let's just say that you shut your door, and then shut all your windows so there isn't any ventilation and stayed in your room for several days. Could you end up breathing until you've reduced the oxygen to dangerous levels?

=\frac{-r\hat{r}}{r^{3}} ?? so it's the negative r unit vector pointing in the r direction.. over r cubed.. right? =( I seem to have a huge knowledge hole about vectors

I don't understand the differences between: \vec{r},\hat{r} and r! =(

I'm thinking hard but I'm not sure.. I'm thinking something along the lines of.. the x-component of \hat{r}.. the y-component. or something? >_<

r^{2} = x^{2}+y^{2}+z^{2}? - \hat{r} = -x \hat{e_1}-y\hat{e_2}-z \hat{e_3}? So final answer: \frac{-\hat{r}}{r^{5/2}} ?

Is this better? I can't figure out how to simplify it further.

Does my solution look correct to you guys? Homework Statement Calculate: \nabla \varphi (r) If: \varphi (r) = \frac{1}{4\pi\epsilon_{0}}\frac{1}{r} with: r = \sqrt{x^{2}+y^{2}+z^{2}} Homework Equations n/a The Attempt at a Solution

Quantum mechanics without really knowing what is going on - that is an accurate description. I'm studying electronic engineering - but we're all forced to take on this subject which is called Electronc Materials. I'm finding it tough with little to no background in Physics. Anyway, I've...

What do you mean by bound states? I'm really sorry to be such a newbie.!

Must I have a value for Vo to find the eigenenergy values? In all the examples my teacher has ever given, he always seems to write Vo, but not actually specify what it is.

yep. S = e^{-a} \ \ \ \ \ -e^{-jk} \ \ \ \ \ -e^{jk} \ \ \ \ \ 0 ae^{-a} \ \ \ \ \ -jke^{-jk} \ \ \ \ \ jke^{jk} \ \ \ \ \ 0 0 \ \ \ \ \ e^{jk} \ \ \ \ \ e^{-jk} \ \ \ \ \ -e^{-a} 0 \ \ \ \ \ jke^{jk} \ \ \ \ \ -jke^{-jk} \ \ \...

the x-axis is Ehat - the energy, normalised. So: Ehat = E \frac{L}{2}, where L is the length of gap in my "well" and the y-axis is detS - the determinant of the matrix I created from the boundary and interface conditions. So each x-axis crossing should give me an energy eigenvalue shouldn't...

Homework Statement I wrote a whole heap of MATLAB code, and I have no idea whether my answers, or the plots of my answers are anywhere in the vicinity of looking right. I was hoping someone with a lil bit of experience in this type of physics would be able to tell me if I'm on the right...

Sorry! I've edited my above post.. Now it makes more sense :) What I'm really after is how did they (my teacher) come up with [E] and what is it? k_hat is apparently a normalised k