What is the formula for calculating average power of electromagnetic waves?

[blackbyron]

Homework Statement

Homework Equations

Savg = Em * Bm / (2*μ0 * c)

The Attempt at a Solution

I solved for S avg without calculating inside the cos, but I got it right.

The z and t is given, but is there the reason why you don't solve inside the cos, or is it the bug? it's makes me confused.

Thanks

 

[ehild]

Savg = Em * Bm / (2*μ0 * c)

What do Savg, Em and Bm mean?

ehild

 

[Spinnor]

See,

http://en.wikipedia.org/wiki/Poynting_vector#Derivation

The only information that was given needed to solve the problem was the maximum electric field, 4.6 volts per meter.

 

[blackbyron]

I see, I look at my teacher's notes and saw the exact equation.

So to solve for Savg, it only cares about the maximum values right?

 

[Spinnor]

Right, the result is independent of frequency or position.

 

[blackbyron]

Thanks for your help.