Final answer:
Without explicit descriptions or numbers of disks, it's impossible to determine which disks have a positive initial angular velocity. Positive angular velocity indicates counterclockwise rotation, according to the right-hand rule in physics.
Step-by-step explanation:
To determine which of the disks have a positive initial angular velocity, we must apply the concept of angular velocity, which in physics is defined as the rate of change of angular displacement and is a vector quantity.
A disk with a positive angular velocity rotates counterclockwise, as per the right-hand rule. When the fingers of your right hand wrap counterclockwise from the x-axis toward the y-axis, your thumb will point in the direction of the positive z-axis.
Consequently, a disk spinning clockwise has a negative angular velocity. Therefore, a positive angular velocity corresponds to a counterclockwise rotation.
Since the problem statements do not provide explicit descriptions or numbers of disks, nor situations describing their rotational directions, I cannot give a direct answer to which disks have a positive initial angular velocity. More context or specific examples would be necessary to determine the angular velocity of particular disks.