\u0394 x c \u0394 t y x z x E B B B A FIGURE 2211 Electromagnetic wave carrying energy

# Δ x c δ t y x z x e b b b a figure 2211

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Δ x = c Δ t y x z x E B B B A FIGURE 22–11 Electromagnetic wave carrying energy through area A. E and B from the Sun. Radiation from the Sun reaches the Earth (above the atmosphere) with an intensity of about Assume that this is a single EM wave, and calculate the maximum values of E and B . APPROACH We solve Eq. 22 8 for in terms of and use SOLUTION From Eq. 22 2, so NOTE Although B has a small numerical value compared to E (because of the way the different units for E and B are defined), B contributes the same energy to the wave as E does, as we saw earlier. B 0 = E 0 c = 1.01 * 10 3 V m 3.00 * 10 8 m s = 3.37 * 10 6 T. B = E c , = 1.01 * 10 3 V m. E 0 = C 2 I 0 c = C 2 A 1350 J s m 2 B A 8.85 * 10 12 C 2 N m 2 BA 3.00 * 10 8 m s B I = 1350 J s m 2 . I E 0 A I = 1 2 0 cE 0 2 B 1350 J s m 2 . 1350 W m 2 = EXAMPLE 22 ; 4 C A U T I O N E and B ha v e v ery different v alues (due to ho w units are defined), but E and B contribute equal energy   #### You've reached the end of your free preview.

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• Spring '14
• Dr.Zhang
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