Aprevious journal article established that a hanging Slinky’s restoring force is due only to the coils between the support and the Slinky’s center of mass (hereafter COM). Correspondingly, it is expected the Slinky’s elastic potential energy (hereafter EPE) is associated with only those coils; however, there is no confirming experimental evidence. The experimental setup, the discussion, and the analysis here provide the confirming experimental evidence. The experimental setup is simple and the analysis is straightforward. Both may be understood by physics and engineering majors who have some familiarity of the COM concept, the EPE of springs, and the ability to calculate the work done by gravitational forces.

1.
Philip
Gash
, “
Let students discover an important physical property of a Slinky
,”
Phys. Teach.
54
,
431
433
(Oct.
2016
).
2.
See Ref. 1, p. 432.
3.
See Ref. 1, p. 432 where in Eq. (9) Na = 0.
4.
Mikolaj
Sawicki
, “
Static elongation of a suspended Slinky
,”
Phys. Teach.
40
,
267
277
(May
2002
).
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