An 800-khz radio signal is detected at a point 8.5 km distant from a transmitter tower. the electric field amplitude of the signal at that point is 0.90 v/m. assume that the signal power is radiated uniformly in all directions and that radio waves incident upon the ground are completely absorbed. what is the average electromagnetic energy density at that point

Light from two different sources are incident upon the same side of a polarizing filter. light from one source is polarized with total intensity ip, while light from the other source is unpolarized with total intensity iu. as you rotate the polarizing filter through 360 degrees, the intensity of the transmitted light on the other side varies by a factor of 9. what is the relative intensity of the initial polarized source to the unpolarized source, or ip/iu?