PURPOSE: To illustrate the dynamics of a SLINKY suspended from one end and released.

DESCRIPTION: A SLINKY is suspended from one end and released from rest. Q: What will happen when the SLINKY is released: (a) The bottom end will begin to accelerate upward as the entire SLINKY collapses, (b) The bottom end will begin to accelerate downward as the entire SLINKY collapses, or (c) The bottom end will remain instantaneously at rest as the SLINKY collapses? A: The bottom end will remain at rest until the entire SLINKY has collapsed, at which time it will begin to accelerate downward.

Click your mouse on the photograph above to view an mpeg video of the action. Because it happens rapidly, you may have to view the video frame-by-frame to verify that the bottom end will not move until the spring is totally collapsed.

SUGGESTIONS:

See Question of the Week #9 for information on using this demonstration to enhance class involvement.

REFERENCES: (PIRA 1G20.45) See Demonstration Reference File for a number of articles discussing this demonstration.

EQUIPMENT: SLINKY.

SETUP TIME: None.