Mechanics > Newton's Laws > Newton's Second Law > Accelerated Reference Frames
 DCS# 1G20.45
DROPPED SLINKY
slinky in midair
APPARATUS
slinky
 101-09-G6
stool or ladder
 202

DESCRIPTION
Hold the slinky by a few turns at its top so it stretches vertically under its own weight.  If released, will the bottom rise, fall, or remain stationary?  Drop the slinky and observe its motion as it falls.  The bottom end remains at rest until the slinky has fully collapsed, and only then begins to fall.

a series of five video stills showing dropped slinky collapsing

Slow motion video at 400 frames/sec:  slowslinky.mov

Slow motion video of longer slinky at 400 frames/sec:  slinky400fps.mp4

There is also a slow motion video of a huge slinky dropped from south window at 1/16 speed.

REFERENCES

TPT 33, 586 (1995).

Am. J. Phys. 80, 1051 (2012)