Recent content by BrokenPhysics

OK thanks, that gives the right units. I've found conflicting expressions: these two pages both have a factor of ##c## and so do the lecture notes I'm working from: http://ocw.usu.edu/physics/classical-mechanics/pdf_lectures/13.pdf https://en.wikipedia.org/wiki/Larmor_precession but this one...

Take a spin-1/2 particle of mass ##m## and charge ##e## and place it in a magnetic field in the ##z## direction so that ##\mathbf B=B\mathbf e_z##. The corresponding Hamiltonian is $$\hat H=\frac{eB}{mc}\hat S_z.$$ This must have units of joules overall, and since the eigenvalues of ##\hat S_z##...

That makes sense. Thanks a lot!

Let's say ##f(x)=ax^2##. Then ##d^2f/dx^2=2a##. Now we can make the change of variables ##y\equiv\sqrt ax## to give ##f(y)=y^2##. Then ##d^2f/dy^2=2##. It follows that ##\frac{d^2f}{dx^2}=a\frac{d^2f}{dy^2},## but I can't replicate this with the chain rule. I would put...