...device consists of two rotat? The drawing shows a device that can be used to measure the speed of a bullet. The device consists of two rotating disks, separated by a distance of d = 0.750 m, and rotating with an angular speed of 85.0 rad/s. The bullet first passes through the left disk and then through the right disk. It is found that the angular displacement between the two bullet holes is ? = 0.200 rad. From these data, determine the speed of the bullet.