With a rod, cord, pulleys, and slotted masses, students can observe and graph exponential growth in the cord tension over a factor of increase as large as several hundred. This experiment is adaptable for use either in algebra-based or calculus-based physics courses, fitting naturally with the study of sliding friction. Significant parts of the activity are accessible to students in physical science and environmental science courses.
References
1.
Albert A.
Bartlett
, “The exponential function—Part I
,” Phys. Teach.
14
, 393
–401
(Oct. 1976
). 2.
George L.
Hazelton
, “A force amplifier: The capstan
,” Phys. Teach.
14
, 432
–433
(Oct. 1976
). 3.
Clifford
Bettis
, “Capstan experiment
,” Am. J. Phys.
49
, 1080
–1081
(Nov. 1981
). 4.
Eugene
Levin
, “Friction experiments with a capstan
,” Am. J. Phys.
59
, 80
–84
(Jan. 1991
). 5.
To see the supplementary appendix, go to http://dx.doi.org/10.1119/1.4914562.
© 2015 American Association of Physics Teachers.
2015
American Association of Physics Teachers
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