A rattleback is a well-known physics toy that has a preferred direction of rotation. If it is spun about a vertical axis in the “wrong” direction, it will slow down, start rocking from end to end, and then spin in the opposite (i.e. preferred) direction. Many articles have been written about rattlebacks. Some are highly mathematical 1, 2 and others are purely descriptive.3–5 It is surprising that there is still no simple physical explanation. By that, I mean an explanation that can be given to a high school student and one that does not involve an obscure set of complicated equations.
REFERENCES
1.
A.
Garcia
and M.
Hubbard
, “Spin reversal of the rattleback Theory and experiment,”
Proc. Roy. Soc. London Ser. A
, 418
(1854
), 165
–197
(1988).2.
L.
Franti
, “On the rotational dynamics of the rattleback,”
Cent. Eur. J. Phys
. 11
, 162
–172
(2013
).3.
H.
Crane
, “The rattleback revisited,”
Phys. Teach.
29
, 278
–279
(May 1991
).4.
R.
Edge
and R.
Childers
, “Curious Celts and riotous rattle-backs,”
Phys. Teach
. 37
, 80 (Feb. 1999
).5.
6.
Viewers can see the videos at TPT online, http://dx.doi.org/10.1119/1.4830068.1 and http://dx.doi.org/10.1119/1.4830068.2
© 2013 American Association of Physics Teachers.
2013
American Association of Physics Teachers
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