What is the Amplitude of the Magnetic Field for a Point Source?

AI Thread Summary
The discussion revolves around calculating the amplitude of the magnetic field and the total power radiated by a point-like source of electromagnetic waves. A detector at 5.6 km measures an intensity of 35.1 μW/m². The amplitude of the magnetic field oscillations is derived from the intensity using the provided equations, but initial attempts yielded incorrect results. The total power radiated by the source can be calculated using the intensity and the surface area of a sphere with a radius of 5600 m. The conversation concludes with the original poster successfully solving both parts of the problem.
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Homework Statement



A point-like source of electromagnetic waves radiates power uniformly in all directions at a single frequency.

At a distance of 5.6 km from the source, a detector measures the intensity (energy flux density) of the wave to be 35.1 μW/m2 (microwatts per square meter).

a)Calculate the amplitude of the magnetic field oscillations of the wave at the detector.

b)What is the total power radiated by the source?

Hint: The intensity (power/area) is c ε0 E0^2/2 where E0 is the amplitude of oscillation of the electric field in the wave. Then the magnetic field is B0=E0/c.

Homework Equations



The relevant equations are given in the "Hint" of the problem. And I used 8.85E-12 for epsilon.

The Attempt at a Solution



I got 0.163 T for the amplitude, but it is wrong. I got 1.425E-12 W for the power, but it is also wrong. Help please.
 
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The power is easy, what is the surface area of a sphere wih radius = 5600m,
If the intensity is 35.1E-6w/m^2 what is the total power for this area, hint the units should come out as watts!
 
Alright, I got a). I cannot figure out b) though.
 
Thanks mgb. I got both parts
 

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