BBi Bj where B 21 X 106 T By36 X106 T and ihat and jhat are

B=(B,i + Bj where B, -2.1 X 106 T, By-3.6 X106 T, and i-hat and j-hat are the unit vectors in the x and y directions, respectively.

Solution

frequncy of the electromagnetic wave is,

   f = speed of light /wavelength = 3*10^8 / 4.2x10^-2 = 7.142e+9 Hz

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intensity of the wave is,

S = B²c/2u⁰

      = [sqrt{Bx^2 + By^2}]*c / 2u⁰

      = 2.073e+3 W/m²

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the z-component of the Poynting vector at (x = 0, y = 0, z = 0) at t = 0:

   Sz = S = 2.073e+3 W/m²

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The x-component of the electric field is,

   Ex = Byc = 2.1x10^-6 * 3x10⁸ = 630 N/C i^