TOPIC:

ID Code: D1-30
Purpose: Show that the instantaneous velocity of an object executing uniform circular motion is tangent to the circle.
Description: A marble is rolled around the inside of the circular band on an overhead projector. When the ball leaves the end of the circular segment it will travel in the direction tangent to the circle at the point where it leaves.
Availability: Available

This relates to another interesting (Though more dangerous to try in the classroom) effect - what happens of you are rotating a mass in a circle at the end of a rope, then cut the rope? fearofphysics.com/BallString/ballstring.html