What is the Period of a Physical Pendulum with a Horizontal Knife-Edge Pivot?

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Joshua A
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Homework Statement



A thin 0.50-kg ring of radius R = 0.60 m hangs vertically from a horizontal knife-edge pivot about which the ring can oscillate freely.

If the amplitude of the motion is kept small, what is the period?

Homework Equations



T = 2pi / ω

Not sure what others...

The Attempt at a Solution



I have no idea what a "horizontal knife-edge pivot" is (I tried to Google it with no success) so I actually don't know where to begin with this problem because I cannot understand what is happening. I'd appreciate an explanation as to what the question means.
 
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Joshua A said:

Homework Statement



A thin 0.50-kg ring of radius R = 0.60 m hangs vertically from a horizontal knife-edge pivot about which the ring can oscillate freely.

If the amplitude of the motion is kept small, what is the period?

Homework Equations



T = 2pi / ω

Not sure what others...

The Attempt at a Solution



I have no idea what a "horizontal knife-edge pivot" is (I tried to Google it with no success) so I actually don't know where to begin with this problem because I cannot understand what is happening. I'd appreciate an explanation as to what the question means.

This is the arrangement. The ring hangs from a knife, the edge of the knife is the pivot. It is a "physical pendulum". http://hyperphysics.phy-astr.gsu.edu/hbase/pendp.html

upload_2017-11-25_9-15-36.png
 
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ehild said:
This is the arrangement. The ring hangs from a knife, the edge of the knife is the pivot. It is a "physical pendulum". http://hyperphysics.phy-astr.gsu.edu/hbase/pendp.html

View attachment 215582

Thank you! I figured out the question now.

Hint for anyone who may stumble upon this thread in the future: when using the equation on the HyperPhysics page, note that it says Isupport. Use the parallel-axis theorem to help you find this.