Recent content by UbikPkd

cool thanks!

sorry! arghh I've made such a mess of this, yer the last two are right, as z=r^2 so it doesn't matter what's being held constant \[ \frac{\partial z}{\partial \vartheta}_{x}=2r^{2}tan\vartheta not 0, sorry, here's my full working: \[ \frac{\partial z}{\partial \vartheta}_{x}=2y\[...

okay thanks for the tip, i worked it out using chain rules in the end before i got to read it, the answers i got were: \[ \frac{\partial z}{\partial x}_{y}=2x \[ \frac{\partial z}{\partial \vartheta}_{x}=0 \[ \frac{\partial z}{\partial r}_{y}=2r \[ \frac{\partial z}{\partial...

Ok here goes... z=x^{2}+y^{2} x=rcos\vartheta y=r sin\vartheta Find: \[ \frac{\partial z}{\partial x}_{y}, \[ \frac{\partial z}{\partial \vartheta}_{x}, \[ \frac{\partial z}{\partial r}_{y}, \[ \frac{\partial z}{\partial r}_{ \vartheta}...

You have to use flemings left hand rule: http://en.wikipedia.org/wiki/Fleming's_left_hand_rule so your 1st finger (field) points in positive x direction (left to right on paper) your second finger (current) points upwards towards the top of the paper and your thumb (motion) points INTO the...

For an atom with one electron and nuclear charge of Z, the Hamiltonian is: H=-~\frac{\nabla^{2}}{2}~- ~\frac{Z}{r}~ 1) show that the wavefunction: \Psi_{1s}=Ne^{-Zr} is an eigenfunction of the Hamiltonian 2) find the corresponding energy 3) find N, the normalisation constant In...

AHHHHHH I've done that so many times, still i haven't learnt, thank you very much, both of you! nrqed i read your blog, a few days ago id never done any quantum, they threw us in by asking for the wave function of the 'particle in a box' . It was a steep learning curve that lasted all night...

ok here goes, i was wary of doing that because, as you can see, that was my first post and it took forever! sorry that last one should have read: \int_0^L ~\frac{2x}{L}~ \sin^{2}(\pi n x / L) dx \int_0^L ~\frac{x}{L}~- ~\frac{x}{L}~ \cos(2 \pi n x / L) dx integrating by parts...

\Psi_{n}(x) = \sqrt{2/L}sin(\pinx/L), 0 \leqx \leq L \Psi_{n}(x) = 0, x<0, x>L \pi is meant to be just normal, not superscript, sorry n is an integer show that <\hat{x}> = L/2 <\hat{x}> is the expectation value of the positional operator \hat{x} right? \hat{x} \Psi= x...