Efficient Pendulum Pivoting for a Frictionless Physics Experiment

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To create a pendulum with minimal friction for a physics experiment, using ball bearings to support the swinging shaft is recommended. A dense material like lead should be used for the pendulum bob to minimize air resistance. The string should be the thinnest and lightest option available, with silk being a suitable choice. A simple setup with a metal clamp can further reduce friction, as it limits the friction to the silk thread's bending. Overall, using lead for the bob and silk for the string is suggested for optimal performance.
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In my physics class we are working on an experiment that deals with energy (kinetic & potential) and right now we need to construct a swinging pendulum that has the least bit of friction to it possible. I have some basic concepts but he said it would cause to much friction that way. Would anyone here have any good ideas to make the pendulum swing with the least amount of friction?
 
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In the immortal words of Fletch: "It's all ball bearings." You can get a relatively inexpensive roller or ball bearing to support the shaft that the pendulum swings on.

If you're not getting that in depth, tell us what your previous idea was and maybe we can expand on it.
 
To minimize air resistance, you want the densest material you can find for the bob. Most likely it would be lead. The string should be the thinnest and lightest combination that can hold the bob. Silk is a good option (available from a sewing/fabric shop. Sometimes simple is best: with a good metal clamp (clamped between two flat metal strips) the only friction is the interior friction of the silk thread bending. THis is very small.

Lead and silk; that's my suggestion.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
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