Recent content by Andrusko

Homework Statement Use the rules for addition of angular momentum vectors to show that there are 12 possible values of (s',l',j') for two electrons with l1=1, l2=3, s1=1/2, s2=1/2. Homework Equations Total Spin S'=S1 + S2 Total orbital angular momentum L'=L1 + L2 Total angular...

Hey thanks for the replies. The conductance (G) was deemed negligible in the question. I think its a 2 part question. Ie; solve for frequency for the phase angle of gamma and then separately solve for frequency for the phase angle of impedance, not that they are both pi/6 at the same time. Or...

It's still not working. Changing the arctan argument yields the same answer. Buggered if I know.

Oh good point. I figured the vector representing gamma would be sitting in the 90 - 180 degrees of the unit circle... but it's not necessarily. That is sneaky...

Okay, here's how much further I've got with it. \gamma^{2} = (R + i\omega L)(i \omega C) \gamma^{2} = R C \omega i - \omega^{2} L C \gamma^{2} = \sqrt{R^{2} C^{2} \omega^{2} + L^{2} C^{2} \omega^{4}} e^{(\pi - arctan(\frac{R}{L \omega}))i} \gamma = (R^{2} C^{2} \omega^{2} +...

Homework Statement A transmission line has the following properties: L_{0} = 1 mHm^{-1} C_{0} = 10 \mu F m^{-1} R_{0} = 10 \Omega m^{-1} G_{0} = 0 \Omega^{-1} m^{-1} That is, inductance per meter, capacitance per metre etc. The line is 10m long. The problem is to find the...

Homework Statement In the ring Z[\sqrt{-3}] find all units and prove that 2 is irreducible but 7 is not. Homework Equations The Attempt at a Solution Well a unit is a non-zero element of the ring that when multiplied by some other non-zero element of the ring gives the unity of...

Homework Statement Rat and Cat move between room 1 and 2 using different paths. Their motions are governed by their respective transition matrices: [0.9, 0.1 ; 0.2, 0.8] [0.6, 0.4 ; 0.3, 0.7] (semi colon is a new line in the matrix, like in matlab) If they are ever in the same room...

Hey all, I'm an absolute noob to number theory stuff and I've got this assignment to do with a few proofs. Homework Statement Proove that: i) if gcd(a,b) = c then gcd(a,a+b) = c ii) if gcd(a,b) = c and a = a'c and b = b'c then gcd(a',b') = 1 iii) if there exists r,s such that rx...

1 atm = 101.325 kPa

Part a is just a graph. Factorize x(t) and solve for the roots (when x(t) = 0) and find the y-intercept (solve x(t) for t=0). v_{avg} = \frac{\Delta x}{\Delta t} = \frac{x_{final} - x_{initial}}{t_{final} - t_{initial}} Have a crack at part b with that. If you can't get it, I'll give you...

Ah, of course! I see now. Thankyou very much!

Homework Statement Sodium, aluminium and silver have work functions of 2.46, 4.08 and 4.73 eV respectively. Which, if any of these metals will emit photoelectrons when irradiated by Balmer-B photons from a hydrogen discharge lamp? Homework Equations Energy = 13.6(\frac{1}{n_{1}^{2}}...

Hmmm. That equation there is not solvable unless you have another equation you can eliminate one of the unknown variables with. Look carefully at the question and see if there any other information you can glean from it. For example, is it implied that one of the velocities is zero at any time...

And use a small angle approximation. That is: sin \theta ~= \theta This is applied when an angle is pretty small.