- #1
LCSphysicist
- 646
- 162
- Homework Statement
- A bar with magnetization M parallel to its symmetric axis rotates (axis z) about an axis perpendicular to it (let's say, axis x). What is the power radiated? w/c >> l
radius r
- Relevant Equations
- .
Ok. I was writing a big text about it, but i will summarize it.
We know that $$P = \frac{\mu \ddot{m}^2 w^4}{12 \pi c^3}$$
We know, as well, that $$\nabla \times M = 0$$.
Also, $$\vec K = M \times \hat \rho = M \hat \phi$$
Total current, I = $K l = M l$.
Magnetic moment, so, $$M l \pi r^2 $$
So, $$|\ddot{m}|^2 = |M w^2 l \pi r^2|^2$$
Finally, just subtitute it on the first equation...
Is this right??
I am asking because it is, after all, electromagnetism... It is never that easy.
We know that $$P = \frac{\mu \ddot{m}^2 w^4}{12 \pi c^3}$$
We know, as well, that $$\nabla \times M = 0$$.
Also, $$\vec K = M \times \hat \rho = M \hat \phi$$
Total current, I = $K l = M l$.
Magnetic moment, so, $$M l \pi r^2 $$
So, $$|\ddot{m}|^2 = |M w^2 l \pi r^2|^2$$
Finally, just subtitute it on the first equation...
Is this right??
I am asking because it is, after all, electromagnetism... It is never that easy.