unfortunately that doesn't help since I don't know what the spinor is for an unpolarized state is.
I think that the two helicity eigenstate spinors I gave in my first post form a complete set, if that's true then any state must be a linear combination of those two states. The question is then...
ok so since I posted this problem I've realized that I can't say the tau is in a left helicity state because helicity is only conserved in the relativistic limit, and we are working in the tau rest frame.
So basically the problem I think boils down to "How do you determine the spinor for the...
I have a question that asks me to calculate the lepton current for the decay of a tau lepton into the tau neutrino and a pion. It asks me to work in the rest frame of the tau lepton, taking the spin to be fully polarized in the +z direction. The lepton current is given by:
j^{u} =...
I'm stuck on a question involving dipoles and what I am guessing to be the method of images...here goes:
The electrical system of a thundercloud can be represented by a vertical dipole consisting of a charge +40C at a height of 10km and a charge of -40C vertically below it at a height of 6km...
unfortunately I think the question demands some more working than that, even if it boils down to that. Since if lifetime=1/probability...well then it's obviously going to be of the form Aexp(B/kT)...but i just need someone to step it through nice and clearly for me. Thanks
Hi guys,
I'm stuck on what should be a reasonably simple question...here it is:
The quality of a certain supermarket product depends on a single thermally
activated process. It can be stored safely for 3 days at 17 degrees C, but only one day at 37 degrees C. How long can it be stored at...
well i thought about it being something to do with greens theorem...hence just do the curl of the vector over the area but the curl doesn't come out to -z0...i just can't link it to the grad of that scalar i gave. Do you care to elaborate on what you're thinking?
but suppose the surroundings are taken to be a large expandable gas. Absorbing some amount of heat will effectively be a near infintesimal change if the surroundings are sufficiently large. So surely the heat can go straight into the surroundings (i.e. air) in a reversible manner like you...
I have a question which asked me to evalute the line integral around the curve x^2+y^2=r^2 (z=z0 (a constant)) of the following vectors:
(0, z^2, 2yz)
and
(yz^2, yx^2, xyz)
the first one I get as 0, and the second one I get as: -pi(r*z0)^2
Those answers I'm pretty sure are right...
surely this is provided that Q is reversible heat?
Look, I'm not very good at thermodynamics at all...so I'm just after a non-fussy explanation. I have written in my notes that because the surroundings tend to be large, it can be assumed that heat exchanged with the surroundings is reversible...
so can i just establish then, are we saying that the heat given out to the surroundings by, say, a hot object closed system cooling (say a cup of water or something...no evaporation for simplicity), that heat is NOT reversible?
Well that can't be the case because I can do calculations on...
nah sorry i just don't understand how a hot object cooling in cold surroundings can be reversible. You're saying that an object that was once hot but is now cold can become hot once again without any energy being supplied to the system which consists of the object and the surroundings...what...
why is it acceptable to assume any heat exchanged with the surroundings of a system is a reversible heat exchange? The only explanation I can find is that it's because the surroundings are essentially unchanged by the heat they absorb...but I don't understand that as an explanation.
I take...
you just state the part in bold without explaining
Cant you see that your explanation is completely independant of the inductor - you describe a situation with current flowing through a resistor, which then dissipitates power. That is all you've described...I can't see any connection in the...