A horse tows a barge in a canal by means of a rope that makes an angle of 15 degrees with the direction of motion of the barge. The tension in the rope is 120 N. How much work is done in moving the barge 1000 m?

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?