1Q10.10 - Inertial Wands

Give one wand to each of two students.  Have them hold the wand at the center and rotate it back and forth.
The student whose wand has the mass in the center will be able to rotate their wand much faster than the student whose wand has the mass located at the ends of the wand.  The clear wands can be used to show the mass locations in the two opaque wands.
Code Number:
1Q10.10
Demo Title:
Inertial Wands
Condition:
Excellent
Principle:
Exchange of Potential and Kinetic Energy, Moments of Inertia
Area of Study:
Mechanics
Equipment:
Inertia wands, inertia wands with clear tubes.
Procedure:

Give one wand to each of two students.  Have them hold the wand at the center and rotate it back and forth.  The student whose wand has the mass in the center will be able to rotate their wand much faster than the student whose wand has the mass located at the ends of the wand.  The clear wands can be used to show the mass locations in the two opaque wands.

References:
  • Thomas K. McCarthy, "Moving Up the Ladder", TPT, Vol. 34, # 8, Nov 1996, p. 503.
  • Ian Thomas, "Another Rolling Paradox", TPT, Vol. 32, # 4, April 1994, p. 200.
  • David R. Lapp, "Moment of Inertia with PVC Pipe and Iron Rebar", TPT, Vol. 32, # 2, Feb. 1994, p. 115.
  • R. D. Edge, "Crystal Sticks", TPT, Vol. 29, # 2, Feb 1991, p. 128.
  • R. D. Edge, "Rotational Inertia", TPT, Vol. 26, # 6, Sep. 1988, p. 405.
  • R. D. Edge, "Moments of Inertia", TPT, Vol. 17, # 9, Dec 1979, p. 599.
  • Walter Q. Quint, "A Demonstration of Moment of Inertia", TPT, Vol. 15, # 9, Dec 1977, p. 546.
  • Robert Ehrlich, "F.19, Moment of Inertia of a Hula Hoop", Turning the World Inside Out, p. 87.
  • Martin C. Sagendorf, "Rotational Inertia",  Physics Demonstration Apparatus, 2009. p. 101.
  • Borishlaw Bilash II, David Maiullo, "Inertial Wands", A Demo a Day: A Year of Physics Demonstrations, p. 162.
  • David R. Lapp, "Moment of Inertia with PVC Pipe and Iron Rebar", Apparatus for Teaching Physics, p. 48, Edited by Karl Mamola.


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