the entrance to a private car is protected by a boom which closes the entrance. the boom can be made to balance by fixing the counterweight a short distance(0.5m) from the pivot on thr main support. if the weight of the boom alone, f, is 400n acts 3.0m from the pilot as shown, calculate counter weight required for the boom to be balanced

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?