A traveling electromagnetic wave in a vacuum has an electric field amplitude of 71.1 V/m. Calculate the intensity S of this wave. Then, determine the amount of energy U that flows through area of 0.0275 m 2 over an interval of 16.5 s, assuming that the area is perpendicular to the direction of wave propagation.

Question

Irvin Burgess

Physics

14 August, 19:33

A traveling electromagnetic wave in a vacuum has an electric field amplitude of 71.1 V/m. Calculate the intensity S of this wave. Then, determine the amount of energy U that flows through area of 0.0275 m 2 over an interval of 16.5 s, assuming that the area is perpendicular to the direction of wave propagation.

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Amanda Barr · Answer 1

For the calculation of I = Erms2 / (cμ0), I get

I = (91.5 / √2) 2 / [ (2.99 x 108) (1.26 x 10-6) ] = 11.07 W/m2

Intensity = 11.07 w/m^2

t = 17.1 s

A = 0.0229 m2

U = energy = IAt = (11.07) (0.0229) (17.1) J = 4.34 J

Energy = 4.34 Joules