How to Calculate RMS Magnetic Field Strength from Sunlight Power Density?

[clayton26]

Homework Statement

the power density of sunlight, at the earth, is roughly 1 kilowatt/meter^2. How large is the rms magnetic field strength?

Homework Equations

The Attempt at a Solution

I tried using the equation for power density S = E(rms)^2=√(εμ), then substituting B(rms)/c for E(rms), and subsequently solving for B(rms). However this does not give me the correct solution and I am now confused

 

[tiny-tim]

hi clayton261!

(try using the X² and X₂ buttons just above the Reply box )

show us your full calculations, and then we'll see what went wrong, and we'll know how to help!