We have frequently enhanced our department's laboratory experiment involving standing transverse waves in a taut horizontal cord. In addition to the standard experiment, students in these labs investigate the surprising concept that the acceleration of a pulse in a chain hanging vertically is a constant and is equal to half the acceleration of gravity.

1.
I. M.
Freeman
, “
Propagation of a transverse pulse along a hanging chain
,”
Phys. Teach.
15
,
545
(
Dec. 1977
).
2.
D.
Halliday
and
R.
Resnick
,
Fundamentals of Physics
, 2nd ed. (
Wiley
,
New York
,
1981
), pp.
313
314
.
3.
J.
Satterly
, “
Some experiments in dynamics, chiefly on vibrations
,”
Am. J. Phys.
18
,
405
416
(
Oct. 1950
).
4.
R. E.
Gibbs
, “
Standing waves on a hanging rope
,”
Phys. Teach.
36
,
108
110
(
Feb. 1998
).
5.
E. J.
Routh
,
The Advanced Part of a Treatise on the Dynamics of a System of Rigid Bodies
(
Dover
,
New York
,
1955
), pp.
403
and 407.
6.
H.
Bailey
, “
Motion of a hanging chain after the free end is given an initial velocity
,”
Am. J. Phys.
68
,
764
767
(
Aug. 2000
).
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