We present a comprehensive analysis of an intriguing classical mechanics problem involving the coupled motion of two blocks. The problem illustrates fundamental physics concepts and theoretical techniques. We solve the equations of motion numerically and gain insight into common misconceptions about this system. The problem provides rich opportunities for student investigations using analytical and numerical methods.

1.
B.
Korsunsky
, “
Brain twisters for physics students
,”
Phys. Teach.
33
,
550
553
(
1995
).
2.
B.
Korsunsky
, “
Ready, set, go! A research-based approach to problem solving
,”
Phys. Teach.
42
,
493
497
(
2004
).
3.
Statistics are based on written replies from 76 students in a calculus-based mechanics class at Santa Clara University. The question was given to them near the end of the term; the students were familiar with standard two-body problems and rotational dynamics.
4.
W. B.
Case
, “
The pumping of a swing from the standing position
,”
Am. J. Phys.
64
,
215
220
(
1996
).
5.
J. R.
Sanmartín
, “
O Botafumeiro: Parametric pumping in the middle ages
,”
Am. J. Phys.
52
,
937
945
(
1984
).
6.
N. B.
Tufillaro
,
T. A.
Abbott
, and
D. J.
Griffiths
, “
Swinging Atwood’s machine
,”
Am. J. Phys.
52
,
895
903
(
1984
).
7.
A. L.
Garcia
,
Numerical Methods for Physics
, 2nd ed. (
Prentice Hall
,
Englewood Cliffs, NJ
,
2000
).
8.
R. H.
Landau
,
M. J.
Paéz
, and
C. C.
Bordeianu
,
Computational Physics: Problem Solving with Computers
, 2nd ed. (
Wiley-VCH
,
Berlin
,
2007
).
9.
H.
Gould
,
J.
Tobochnik
, and
W.
Christian
,
An Introduction to Computer Simulation Methods
, 3rd ed. (
Addison-Wesley
,
Reading
,
2007
).
10.
F. M. S.
Lima
and
P.
Arun
, “
An accurate formula for the period of a simple pendulum oscillating beyond the small angle regime
,”
Am. J. Phys.
74
,
892
895
(
2006
).
AAPT members receive access to the American Journal of Physics and The Physics Teacher as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.