Question

A sinusoidal electromagnetic wave from a radio station passes perpendicularly through an open window that has area of 0.600 m2 At the window, the electric field of the wave has an rms value 0.0600 V/m Part A How much energy does this wave carry through the window during a 30.0-s commercial? Express your answer with the appropriate units. HA ? Value Units U= Request Answer Submit Provide Feedback Next>

Answer 1

First of all, we find the intensity of the wave

I = $\epsilon$ _ocE²

where c is speed of light

I = 8.85e-12 * 3e8 * 0.06²

I = 9.558e-6 W/m²

so,

energy, U = IAt

where A is area and t is time

U = 9.558e-6 * 0.6 * 30

U = 1.72e-4 J