Why Is the Angular Velocity of a Clockwise-Spinning CD in the -y Direction?

[Qnslaught]

Homework Statement

A CD player spins a disc in a clockwise direction when looking at the player from the top. What is the direction of the angular velocity.

Homework Equations

The Attempt at a Solution

OK, the key for this practice exam says the answer is in the -y direction. I used the right hand rule to see that the direction is negative, but I thought it would be in the -z direction. Can someone explain why it is -y?

 

[SeanGillespie]

I believe they have made the answer this way as you are only using two dimensions. If you take the vertical y-axis as the axle for the rotation, your right thumb will be pointing in the negative y-direction when you use the right hand rule.