# Problem: An AM radio transmitter broadcasts 50.0 kW of power uniformly in all directions. (a) Assuming all of the radio waves that strike the ground are completely absorbed, and that there is no absorption by the atmosphere or other objects, what is the intensity 30.0 km away? (Hint: Half the power will be spread over the area of a hemisphere.) (b) What is the maximum electric field strength at this distance?

###### FREE Expert Solution

Intensity:

$\overline{){\mathbf{I}}{\mathbf{=}}\frac{\mathbf{P}}{\mathbf{A}}}$

(a)

The power is transmitted uniformly in all directions, thereby creating a spherical area.

The area of the sphere is, A = 4πr2

A = (4π)(30.0 × 103)2 = 1.13 × 1010 m2

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###### Problem Details

An AM radio transmitter broadcasts 50.0 kW of power uniformly in all directions.

(a) Assuming all of the radio waves that strike the ground are completely absorbed, and that there is no absorption by the atmosphere or other objects, what is the intensity 30.0 km away? (Hint: Half the power will be spread over the area of a hemisphere.)

(b) What is the maximum electric field strength at this distance?