While the three laws of conservation of energy, momentum, and angular momentum are all mentioned in introductory textbooks, there are few experiments through which students can investigate the conservation of angular momentum. Most experiments consist of collisions between rotating disks, in which one disk is dropped on another, or in which the rotational inertia of a single object is changed and the resulting change in angular velocity measured. This paper presents a method for studying collisions that centers on the conservation of angular momentum, and of rotational energy.