Recent content by fishh

The magnitude of the wave is only constant across planes perpendicular to the wave's motion. The magnitude of the E and B fields still vary sinusoidally with z (parallel planes with a different z component have a different magnitude), so shouldn't the magnitude of the Poynting vector change with z?

I think it is a vector field, as every z position has a different E and B field and thus, a different Poynting vector. I'm not sure if the calculation I did was correct; a plane wave should not have a constant Poynting vector, as there are points where the E and B field are 0, and the...

Well that's true, but if I have an E-field like E_0 \hat{x} e^{-i(kz -\omega t)} And consequently, a B-field like B_0 \hat{y} e^{-i(kz - \omega t)} Then shouldn't the magnitude of the Poynting vector just be |\mathbf{S}| = |\mathbf{E}||\mathbf{H}| = \frac{E_0 B_0}{\mu_0}?

Suppose I have a monochromatic electromagnetic plane wave with the E-field linearly polarized in the x-direction (and the B-field linearly polarized in the y-direction). Then the Poynting vector should be pointing in the z direction with a magnitude equal to the product of the B and E-field...

Thanks, I got the right answer using 4 pi r^2. I guess I should review my geometry...

Homework Statement A 100 W incandescent light bulb converts approximately 2.5% of the electrical energy supplied to it into visible light. Assume that the average wavelength of the emitted light is λ = 530 nm, and that the light is radiated uniformily in all directions. How many photons per...