- #1
greypilgrim
- 513
- 36
Hi.
I'm a bit puzzled that the classical formula for the intensity of a monochromatic, linear EM wave
$$I=\frac{1}{2}\cdot c\cdot \varepsilon_0\cdot E_0 ^2$$
seems to be independent of frequency whereas I find for the energy of a mechanical wave (e.g. on a string with total mass ##M##)
$$E=2\pi^2\cdot f^2\cdot A^2\cdot M\enspace .$$
Am I comparing apples and oranges or is it true that the energy transmitted per second per unit area only depends on the amplitude of the electric field?
I'm a bit puzzled that the classical formula for the intensity of a monochromatic, linear EM wave
$$I=\frac{1}{2}\cdot c\cdot \varepsilon_0\cdot E_0 ^2$$
seems to be independent of frequency whereas I find for the energy of a mechanical wave (e.g. on a string with total mass ##M##)
$$E=2\pi^2\cdot f^2\cdot A^2\cdot M\enspace .$$
Am I comparing apples and oranges or is it true that the energy transmitted per second per unit area only depends on the amplitude of the electric field?