Recent content by Fr34k

kγ and oν are just arbitrary vectors. I think I kinda get this notation now. As for mathematics behind I couldn't agree more. The problem is we (the students) first saw this kind of notation when actually studying scattering of Dirac particles and didn't really get much (or any) of the...

My bad, you re right it is an expression. I should have said evaluate the expression or simplify or something similar. As for index \nu. Doesn't o =γ\nuo? Would really appreciate some help here.

Homework Statement Solve the equation. What is it's trace?Homework Equations k γμ γ5 o γ\nu γ5 The Attempt at a Solution I don't think this is reduced enough. γμkμγ5γ\nuo\nuγ\nuγ5 trace: just got rid of gamma5 with anticommutation. -Tr[γμkμγ\nuo\nuγ\nu]

Ah sorry for the confusion I caused, in my language velocity and speed mean the same and I immediately assumed you were talking bout speed. Vocabulary updated :) Yes in this case average velocity is 0.

What if that 8 times quarter mile circular track would just be 2 mile long straight track? Would average velocity in that case, with your understanding also be 0? What if track is just one big circle, or figure 8? Or some random curve that is connected? I think I know where are you getting...

8(laps) * 1/4 mile/lap =2 miles This is the distance he traveled, doesn't matter if its circular. 2miles/0.42h=0.833mph This is the average speed. Whole distance divided by time he needed.

I will just paste the link, cause its faster this way: http://scienceworld.wolfram.com/physics/PlanckLaw.html The last equation for spectral energy density if you look at the units you get eVs/m^3 or Js/m^3, yet energy density is supposed to be J/m^3. What am I missing here?

Done it some time ago but I'll post what I did if someone else will have same problems. The essential thing is to break the partial equation down into sum of components each solving a part of the whole. one for boundary conditions + one laplace for stationary solution + one time dependant...

The photons are used when you want to describe interactions of particles. Ie. if you have 2 electrons with their own electric fields. "How do they know where and what the other one is"? It's easier for us to imagine that they exchange something that gives both a sense of their surroundings, in...

Homework Statement Lets say we have a 2D rectangular plate with a point heat source and some boundary conditions. I would like to solve and understand step by step the solution to this second order differential equation. Let's say dimensions of rectangular are a and b. 2 opposite sides are at...

Well I am doing some research for school, and many of the papers I've been reading have the same equation and associated graphs with it and it's never explained why exactly in this form. From what I managed to come up with is some sort of attenuation of atmosphere.

Really no one can explain this to me? Anyone know of a good book on the subject (lidar, atmosphere research ...) where this might be explained.

Yes the time would remain the same. If the force is perpendicular to the gravity then the time is the same.

Yes really. Imagine a net x,y,z. and let's say you have 3 rocks. You re at a point (0,0,10) 1st one you drop. Drops at (0,0,0) in some amount of time. 2nd you throw parallel to the x,y grid but only in x direction. So it drops somewhere (x,0,0) in a different time (by your understanding)...

The first ball does cover more distance but in the same amount of time then the second ball. They fall on the ground the same time because there is the same down force on them. The horizontal force is not added to the vertical force. In other words the horizontal force does not magically add to...