We present an experimental method to obtain the effective mass of an unloaded oscillating spring. We measure the period T(n) of the partial springs that result when hanging n of the total N coils of a given spring. Data are correlated with the expectation of a simple model for T(n) that takes into account the effective mass of the hanging spring. We analyze results for metal and plastic springs of different masses and strengths, and conclude that the method provides the effective mass with a good degree of reliability.
REFERENCES
1.
F. Sears, M. Zemansky, and H. Young, University Physics (Addison-Wesley, Reading, MA, 1976).
2.
See, for example,
J.
Christensen
, “An improved calculation of the mass for the resonant spring pendulum
,” Am. J. Phys.
72
, 818
–878
(June 2004
).3.
E. E.
Galloni
and M.
Kohen
, “Influence of the mass of the spring on its static and dynamic effects
,” Am. J. Phys.
47
, 1076
–1078
(Dec. 1979
).4.
L.
Ruby
, “Equivalent mass of a coil spring
,” Phys. Teach.
38
, 140
–141
(March 2000
).
This content is only available via PDF.
© 2007 American Association of Physics Teachers.
2007
American Association of Physics Teachers
AAPT members receive access to The Physics Teacher and the American Journal of Physics as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.