Energy carried by Electromagnetic Waves

AI Thread Summary
The discussion revolves around calculating the rms values of the electric field (E) and magnetic field (B) in an electromagnetic wave emitted by an industrial laser with an average light density of S = 1.24E9 W/m2. The formula S = ceoE^2 is used to derive E, resulting in 683405.7 N/C, while B is calculated using the relationship E = cB, yielding a value of 0.00228 T. It is noted that significant figures are crucial for the accuracy of the answer for E. The user is seeking confirmation to ensure all necessary details are included before submitting their final attempt. Accurate calculations and attention to significant figures are essential for successful completion of the homework.
Gannon
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Homework Statement


An industrial laser is used to burn a hole through a piece of metal. The average density of the light is S = 1.24E9 W/m2. What is the rms value of each of the following fields in the electromagnetic wave emitted by the laser?


Homework Equations


S = ceoE2
S = (c/uo)B2
E=cB
S is average density and E,B are rms values.

The Attempt at a Solution


Solving for E:
sqrt(S/ceo) = E
sqrt(1.24E9/(3e8 x 8.85E-12)) = E = 683405.7 N/C

Solving for B:
E = cB
E/C = B
4.67E11/3E8 = .00228T

I have 5 tries to get this homework right and I'm down to my last one. I want to make sure I'm not leaving anything out this time. Any help is appreciated!
 
Physics news on Phys.org
Looks good. You might need to watch the significant figures on the answer for E, they checked for that.
 

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