I don't think the science teachers are going to appreciate talking about a "centrifugal force". that's only in the frame of reference of the spinner. in our frame of reference there's no such thing...
I've got to explain how spin art works to some 5th graders tomorrow.
Basic setup: Paper is attached to center of a horizontal disk. Paint droplets are placed at different places on the paper. Disk is spun which causes paint to produce a pattern flowing away from the center of the disk/paper...