Recent content by loonychune

Actually, I see it now. Bringing the two systems into thermal contact means they can exchange energy, so we have to sum over all the possible discrete energies. e.g. n_A = 3, n_B = 4 \rightarrow n_{A,NEW} = 0, n_{B,NEW} = 7 is a new possible arrangement.

Two Einstein solids are joined so that they can exchange energy. One contains N_A oscillators, the other N_B oscillators. Apparently, the possible number of quantum states of the combined system is given by, g(n,N) = \sum_{n_A = 0}^n g(N_A,n_A)g(N_B,n-n_A) where n is the principal quantum...

I'd recommend searching for a philosophy paper by Richard Taylor titled Spatial and Temporal Analogies or something close. He argues that time is like space but at the very least you'll encounter a few arguments that are, in sum, ridiculous-sounding. However the point is, you find it hard...

There is, soldered to each end of the germanium bar, two OHMIC contacts. A 'sweeping' electric field pulse is applied across the bar using the ohmic contacts. The actual emitter and collector contacts (essentially two metal pins) are partially rectifying and usually represented as diodes. Does...

I'm measuring the drift velocity of holes in n-type Germanium using the Shockley-Haynes technique. Two metal point contacts are placed some distance apart on a germanium bar. The collector is negative biased owing to it being connected to a 9V battery. The emitter is connected to a pulse...

You can break this problem down into its component constituents... the force due to gravity acts only in the j direction, so when this particle is displaced 3.80m in the i direction, in 1.20s, for which the acceleration is constant (because force is constant), you have: 3.80 =...

I don't mean to be an arse and force the issue, but I have the idea that, since the particle IS at rest at x = 0 and should in fact be at a maximum here but isn't until the sine function 'catches up' then some of the kinetic energy goes into just moving the electron and not oscillating (which it...

Well for n = 3... Set l = 2: then m can take on the range of: -2,-1,0,1,2 Set l = 1: m = {-1,0,1} l = 0: m = 0 There's 9 states. EDIT: Think of, for n = 3, every independent quantum state by labelling your state: \psi_{n,l,m}: \psi_{3,0,0} \neq \psi_{3,1,-1} \neq...

s = \frac{1}{2}(u+v)t ...one of the SUVAT equations for constant acceleration... this is esentially what you've used to find t... and it does give 8.278 * 10^{-9}... so i'd probably move on to something else unless someone else has owt to say

Thanks for your reply. I'm still none the wiser however. If you would, pick out the stages in the following and explain where we couldn't in fact do that. An electron with mass m is initially at rest in the ionosphere. It is suddenly subjected to an electric field, E =...

I should probably be a little clearer as to the velocity of the electron: v(t) = \frac{a_0}{\omega} -\frac{a_0}{\omega}\cos\omega t EDIT: Something to ponder: If the electric field we apply is: E = E_0\cos\omega t then the resulting velocity is: v(t) =...

Just hoping you might explain the physics here for me. An electron is placed in an oscillating electric field, say, E = E_0\sin(\omega t) and as a result accelerates in x at, a = a_0\sin(\omega t) (grouped some constants in a_0). Solving for the resulting motion yields, x =...

This ought really be like gold to you: http://www.ocr.org.uk/qualifications/as_alevelgce/physics_b_advancing_physics/documents.html There's a good 6 or 7 past papers there with the mark schemes. It'll be good practice to do them anyway and test yourself and you'll probably find that...

I have found some textbooks we used in class and they're what I used -- instead of notes, because they were poor -- to learn physics. http://www.amazon.com/dp/0521787181/?tag=pfamazon01-20 http://www.amazon.com/dp/0521797152/?tag=pfamazon01-20 They might not be as useful to you if you are...

You got Cs in AS maths and AS physics? What were your actual marks out of 300? If you got 209, you're going to need at least 90 on each module you do in maths and physics this year... so i'd recommend re-sitting a good chunk of your AS modules (which doesn't change your 'AS Grade' but if you...