A starfleet battle-cruiser drops out of hyperspace in the orbital plane of a ringworld, traveling at 1 ly/ty radially away from the ringworld's star. An enemy cruiser drops out of hyperspace nearby at the same time, traveling 1 ly/ty in the rotation-direction of the ringworld's orbit, and in a direction perpendicular to the starfleet cruiser's radial-trajectory . What is the proper-velocity (magnitude and direction) of the enemy cruiser relative to the starfleet ship?