Bifilar pendulum experiment

AI Thread Summary
The bifilar pendulum experiment shows data that aligns well with theoretical predictions. A question arises regarding the expected period of the bifilar pendulum matching that of a torsional pendulum when the support strings are at the same point. The user struggles to derive the bifilar equation into the torsional equation under this condition. It is noted that when the strings are attached at a single point, the motion resembles that of a simple ball-on-string pendulum. Clarification is sought on the ball-on-string problem, as existing online resources are unclear.
houlahound
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Bifilar pendulum, data matches the theory real neat. Do have a question, I would expect the period to match the period of a torsional pendulum for the limit when the support strings are the same point ie zero separation.

I can't get the bifilar equation to reduce to the torsion equation for said limit. Any clues?
 
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if the 2 pendulum strings are attached at the same point, it has become a simple ball-on-string pendulum.
(the bifilar's ball motion is the same as for a single string, if the string is shorter.)
A torsional pendulum's Restoring Force is caused by a thick support's rotational elasticity, rather than gravity.
 
Not aware of the ball on string problem, google gave ambiguous results. Do you have link?
 
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