An electromagnetic wave has an electric field with peak value 250 N/C. ?

Question

What is the average energy delivered to a surface with area 2.00 m^2 by this wave in one minute?

Answer 1

The energy flux of an electromagnetic wave is given by the Poynting vector. Its time averaged magnitude is:

|S| = (1/2)∙ε₀∙c∙E₀²

ε₀ permittivity, c speed of light, E₀ peak value of the electric field.

Multiply by the area and you get the power you're are looking for:

P = (1/2)∙ε₀∙c∙E₀²∙A

= (1/2) ∙ 8.8542×10⁻¹²C²N⁻¹m⁻²  Ã¢ÂˆÂ™ 2.998ms⁻¹ ∙ (250NC⁻¹)² ∙ 2.0m²

= 331.8 Nms⁻¹ = 331.8W