A car is moving at constant velocity on a level road. The driver now heads up a ramp to a bridge. If the frictional force remains the same and the car continues at the same constant velocity, is the engine producing more forward force than before, less than before, or the same amount? Use force diagrams to explain your answer.

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?