![[American Journal of Physics December 2012]](ajpcov_dec2012_thumb.jpg)
American
Journal of Physics, 80, 12, Dec 2012, featuring Rod Cross on the
cover.
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Falling slinkies reveal interesting dynamics. If a slinky initially
suspended from its top is released, the bottom of the slinky does not fall
until the collapsing top section collides with the bottom
(movie at lower left).
The tension in the spring collapses from the top downwards, behind a wave
front which runs down the slinky. A semi-analytic model for the fall was
presented by Calkin (Am. J. Phys. 61, 261, 1993). I worked recently
with Rod Cross
on improving this model - including a finite time for
collapse of the slinky turns behind the front - and fitting the model
to data extracted from high-speed movies of real falling slinkies. The
results are presented in a
paper (Cross and Wheatland,
Am. J. Phys. 80, 1051, 2012). [The AJP pdf is available
subject to
this
copyright.] A short account of the modeling was given in a
Research Bite talk in the School of Physics at the University of
Sydney.
The links below include Rod's movies of the falls of two real slinkies,
which provided the data used in the paper, simulation movies of models
described in the paper, and two videos from the
Veritasium YouTube channel run by Derek Muller.
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![[American Journal of Physics December 2012]](ajpcov_dec2012.jpg)
![[Fall of the plastic rainbow-coloured slinky]](rainbow_cat.jpg)
