The ball of mass mb approaches the disks at an angle with respect to the tangent line to the disk and rebounds at an angle with respect to the normal. The ball's initial speed is v0, and its final speed is vf. What is the new z-component of the angular velocity of the system of rotating disks (they still rotate together) after the collision with the ball? Use these values for the parameters:

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?